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H5T: Datatype Interface

Datatype Object API Functions

These functions create and manipulate the datatype which describes elements of a dataset.
In the following lists, italic type indicates a configurable macro.

The C Interfaces:
General Datatype Operations
  • H5Tcreate
  • H5Topen
  • H5Topen1  *
  • H5Topen2
  • H5Tcommit
  • H5Tcommit1  *
  • H5Tcommit2
  • H5Tcommit_anon
  • H5Tcommitted
  • H5Tcopy
  • H5Tequal
  • H5Tlock
  • H5Tget_class
  • H5Tget_create_plist
  • H5Tset_size
  • H5Tget_size
  • H5Tget_super
  • H5Tget_native_type
  • H5Tdetect_class
  • H5Tclose

    Conversion Functions
  • H5Tconvert
  • H5Tfind
  • H5Tcompiler_conv
  • H5Tregister
  • H5Tunregister
  • H5Tdecode
  • H5Tencode
  •        Atomic Datatype Properties
  • H5Tget_order
  • H5Tset_order
  • H5Tget_precision
  • H5Tset_precision
  • H5Tget_offset
  • H5Tset_offset
  • H5Tget_pad
  • H5Tset_pad
  • H5Tget_sign
  • H5Tset_sign
  • H5Tget_fields
  • H5Tset_fields
  • H5Tget_ebias
  • H5Tset_ebias
  • H5Tget_norm
  • H5Tset_norm
  • H5Tget_inpad
  • H5Tset_inpad
  • H5Tget_cset
  • H5Tset_cset
  • H5Tget_strpad
  • H5Tset_strpad
  • H5Tis_variable_str

    Array Datatypes
  • H5Tarray_create
  • H5Tarray_create1  *
  • H5Tarray_create2
  • H5Tget_array_ndims
  • H5Tget_array_dims
  • H5Tget_array_dims1  *
  • H5Tget_array_dims2
  •        Compound Datatype Properties
  • H5Tget_nmembers
  • H5Tget_member_class
  • H5Tget_member_name
  • H5Tget_member_index
  • H5Tget_member_offset
  • H5Tget_member_type
  • H5Tinsert
  • H5Tpack

    Variable-length Array Datatypes
  • H5Tvlen_create

    Opaque Datatypes
  • H5Tset_tag
  • H5Tget_tag

    Enumeration Datatypes
  • H5Tenum_create
  • H5Tenum_insert
  • H5Tenum_nameof
  • H5Tenum_valueof
  • H5Tget_member_value
  • H5Tget_nmembers
  • H5Tget_member_name
  • H5Tget_member_index
     
     
        *   Use of these functions
              is deprecated in
              Release 1.8.0.

  • Alphabetical Listing
  • H5Tarray_create
  • H5Tarray_create1  *
  • H5Tarray_create2
  • H5Tclose
  • H5Tcommit
  • H5Tcommit1  *
  • H5Tcommit2
  • H5Tcommit_anon
  • H5Tcommitted
  • H5Tcompiler_conv
  • H5Tconvert
  • H5Tcopy
  • H5Tcreate
  • H5Tdecode
  • H5Tdetect_class
  • H5Tencode
  • H5Tenum_create
  • H5Tenum_insert
  • H5Tenum_nameof
  • H5Tenum_valueof
  • H5Tequal
  • H5Tfind
  • H5Tget_array_dims
  • H5Tget_array_dims1  *
  • H5Tget_array_dims2
  •       
  • H5Tget_array_ndims
  • H5Tget_class
  • H5Tget_create_plist
  • H5Tget_cset
  • H5Tget_ebias
  • H5Tget_fields
  • H5Tget_inpad
  • H5Tget_member_class
  • H5Tget_member_index
  • H5Tget_member_name
  • H5Tget_member_offset
  • H5Tget_member_type
  • H5Tget_member_value
  • H5Tget_native_type
  • H5Tget_nmembers
  • H5Tget_norm
  • H5Tget_offset
  • H5Tget_order
  • H5Tget_pad
  • H5Tget_precision
  • H5Tget_sign
  • H5Tget_size
  • H5Tget_strpad
  • H5Tget_super
  • H5Tget_tag
  •       
  • H5Tinsert
  • H5Tis_variable_str
  • H5Tlock
  • H5Topen
  • H5Topen1  *
  • H5Topen2
  • H5Tpack
  • H5Tregister
  • H5Tset_cset
  • H5Tset_ebias
  • H5Tset_fields
  • H5Tset_inpad
  • H5Tset_norm
  • H5Tset_offset
  • H5Tset_order
  • H5Tset_pad
  • H5Tset_precision
  • H5Tset_sign
  • H5Tset_size
  • H5Tset_strpad
  • H5Tset_tag
  • H5Tunregister
  • H5Tvlen_create

  • The Fortran Interface:
    In general, each Fortran subroutine performs exactly the same task as the corresponding C function.
    General Datatype Operations
  • h5tcreate_f
  • h5tdecode_f
  • h5tencode_f
  • h5topen_f
  • h5tcommit_f
  • h5tcommit_anon_f
  • h5tcommitted_f
  • H5tcompiler_conv_f
  • h5tcopy_f
  • h5tequal_f
  • h5tget_create_plist_f
  • h5tget_class_f
  • h5tset_size_f
  • h5tget_size_f
  • h5tget_super_f
  • h5tclose_f

    Enumeration Datatypes
  • h5tenum_create_f
  • h5tenum_insert_f
  • h5tenum_nameof_f
  • h5tenum_valueof_f
  • h5tget_member_value_f
  • h5tget_native_type_f
  • h5tget_nmembers_f
  • h5tget_member_name_f
  • h5tget_member_index_f
  •        Atomic Datatype Properties
  • h5tget_order_f
  • h5tset_order_f
  • h5tget_precision_f
  • h5tset_precision_f
  • h5tget_offset_f
  • h5tset_offset_f
  • h5tget_pad_f
  • h5tset_pad_f
  • h5tget_sign_f
  • h5tset_sign_f
  • h5tget_fields_f
  • h5tset_fields_f
  • h5tget_ebiass_f
  • h5tset_ebiass_f
  • h5tget_norm_f
  • h5tset_norm_f
  • h5tget_inpad_f
  • h5tset_inpad_f
  • h5tget_cset_f
  • h5tset_cset_f
  • h5tget_strpad_f
  • h5tset_strpad_f
  • h5tis_variable_str_f
  •        Array Datatypes
  • h5tarray_create_f
  • h5tget_array_ndims_f
  • h5tget_array_dims_f

    Compound Datatype Properties
  • h5tget_nmembers_f
  • h5tget_member_class_f
  • h5tget_member_name_f
  • h5tget_member_index_f
  • h5tget_member_offset_f
  • h5tget_member_type_f
  • h5tinsert_f
  • h5tpack_f

    Variable-length Array Datatypes
  • h5tvlen_create_f

    Opaque Datatypes
  • h5tset_tag_f
  • h5tget_tag_f

    Conversion Subroutines
  • h5tconvert_f
  • The Datatype interface, H5T, provides a mechanism to describe the storage format of individual data points of a data set and is hopefully designed in such a way as to allow new features to be easily added without disrupting applications that use the data type interface. A dataset (the H5D interface) is composed of a collection or raw data points of homogeneous type organized according to the data space (the H5S interface).

    A datatype is a collection of datatype properties, all of which can be stored on disk, and which when taken as a whole, provide complete information for data conversion to or from that datatype. The interface provides functions to set and query properties of a datatype.

    A data point is an instance of a datatype, which is an instance of a type class. We have defined a set of type classes and properties which can be extended at a later time. The atomic type classes are those which describe types which cannot be decomposed at the datatype interface level; all other classes are compound.

    See The Datatype Interface (H5T) in the HDF5 User's Guide for further information, including a complete list of all supported datatypes.


    Creating variable-length string datatypes
    Last modified: 25 September 2012

    As the term implies, variable-length strings are strings of varying lengths; they can be arbitrarily long, anywhere from 1 character to thousands of characters.

    HDF5 provides the ability to create a variable-length string datatype. Like all string datatypes, this type is based on the atomic string datatype: H5T_C_S1 in C or H5T_FORTRAN_S1 in Fortran. While these datatypes default to one character in size, they can be resized to specific fixed lengths or to variable length.

    Variable-length strings will transparently accommodate ASCII strings or UTF-8 strings. This characteristic is set with H5Tset_cset in the process of creating the datatype.

    The following HDF5 calls create a C-style variable-length string datatype, vls_type_c_id:

        vls_type_c_id = H5Tcopy(H5T_C_S1)
        status        = H5Tset_size(vls_type_c_id, H5T_VARIABLE) 
    In a C environment, variable-length strings will always be NULL-terminated, so the buffer to hold such a string must be one byte larger than the string itself to accommodate the NULL terminator.

    In Fortran, strings are normally of fixed length. Variable-length strings come into play only when data is shared with a C application that uses them. For such situations, the datatype class H5T_STRING is predefined by the HDF5 Library to accommodate variable-length strings. The first HDF5 call below creates a Fortran string, vls_type_f_id, that will handle variable-length string data. The second call sets the string padding value to space padding:

        h5tcopy_f(H5T_STRING, vls_type_f_id, hdferr)
        h5tset_strpad_f(vls_type_f_id, H5T_STR_SPACEPAD_F, hdferr) 
    While Fortran-style strings are generally space-padded, they may be NULL-terminated in cases where the data is also used in a C environment.

    Note:   Under the covers, variable-length strings are stored in a heap, potentially impacting efficiency in the following ways:


    Name: H5Tarray_create
    Signatures:
    hid_t H5Tarray_create( hid_t base_type_id, int rank, const hsize_t dims[/*rank*/], const int perm[/*rank*/] )
     
    [1]
    hid_t H5Tarray_create( hid_t base_typ_id, unsigned rank, const hsize_t dims[/*rank*/], ) [2]

    Purpose:
    Creates an array datatype object.

    Description:
    H5Tarray_create is a macro that is mapped to either H5Tarray_create1 or H5Tarray_create2, depending on the needs of the application.

    Such macros are provided to facilitate application compatibility. For example:

    Macro use and mappings are fully described in “API Compatibility Macros in HDF5”; we urge you to read that document closely.

    When both the HDF5 Library and the application are built and installed with no specific compatibility flags, H5Tarray_create is mapped to the most recent version of the function, currently H5Tarray_create2. If the library and/or application is compiled for Release 1.6 emulation, H5Tarray_create will be mapped to H5Tarray_create1. Function-specific flags are available to override these settings on a function-by-function basis when the application is compiled.

    Specific compile-time compatibility flags and the resulting mappings are as follows:

    Compatibility setting H5Tarray_create mapping

    Global settings
    No compatibility flag H5Tarray_create2 
    Enable deprecated symbols H5Tarray_create2 
    Disable deprecated symbols H5Tarray_create2 
    Emulate Release 1.6 interface H5Tarray_create1 

    Function-level macros
    H5Tarray_create_vers = 2     H5Tarray_create2
    H5Tarray_create_vers = 1 H5Tarray_create1

    Interface history:   Signature [1] above is the original H5Tarray_create interface and the only interface available prior to HDF5 Release 1.8.0. This signature and the corresponding function are now deprecated but will remain directly callable as H5Tarray_create1.

    Signature [2] above was introduced with HDF5 Release 1.8.0 and is the recommended and default interface. It is directly callable as H5Tarray_create2.

    See “API Compatibility Macros in HDF5” for circumstances under which either of these functions might not be available in an installed instance of the HDF5 Library.

    Fortran90 Interface: h5tarray_create_f
    SUBROUTINE h5tarray_create_f(base_id, rank, dims, type_id, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: base_id   ! Identifier of array base datatype
      INTEGER, INTENT(IN)        ::  rank     ! Rank of the array
      INTEGER(HSIZE_T), DIMENSION(*), INTENT(IN) :: dims 
                                              ! Sizes of each array dimension
      INTEGER(HID_T), INTENT(OUT) :: type_id  ! Identifier of the array datatype
      INTEGER, INTENT(OUT)        :: hdferr   ! Error code
    END SUBROUTINE h5tarray_create_f
    	

    History:
    Release     C
    1.8.0 The function H5Tarray_create renamed to H5Tarray_create1 and deprecated in this release.
    The macro H5Tarray_create and the function H5Tarray_create2 introduced in this release.

    Name: H5Tarray_create1
    Signature:
    hid_t H5Tarray_create1( hid_t base_type_id, int rank, const hsize_t dims[/*rank*/], const int perm[/*rank*/] )

    Purpose:
    Creates an array datatype object.

    Notice:
    This function is renamed from H5Tarray_create and deprecated in favor of the function H5Tarray_create2 or the new macro H5Tarray_create.

    Description:
    H5Tarray_create1 creates a new array datatype object.

    base_type_id is the datatype of every element of the array, i.e., of the number at each position in the array.

    rank is the number of dimensions and the size of each dimension is specified in the array dims. The value of rank is currently limited to H5S_MAX_RANK and must be greater than 0 (zero). All dimension sizes specified in dims must be greater than 0 (zero).

    The array perm is designed to contain the dimension permutation, i.e. C versus FORTRAN array order.   (The parameter perm is currently unused and is not yet implemented.)

    Parameters:

    Returns:
    Returns a valid datatype identifier if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tarray_create_f
    SUBROUTINE h5tarray_create_f(base_id, rank, dims, type_id, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: base_id   ! Identifier of array base datatype
      INTEGER, INTENT(IN)        ::  rank     ! Rank of the array
      INTEGER(HSIZE_T), DIMENSION(*), INTENT(IN) :: dims 
                                              ! Sizes of each array dimension
      INTEGER(HID_T), INTENT(OUT) :: type_id  ! Identifier of the array datatype
      INTEGER, INTENT(OUT)        :: hdferr   ! Error code
    END SUBROUTINE h5tarray_create_f
    	

    History:

    Last modified: 9 April 2009
    Name: H5Tarray_create2
    Signature:
    hid_t H5Tarray_create2( hid_t base_type_id, unsigned rank, const hsize_t dims[/*rank*/] )

    Purpose:
    Creates an array datatype object.

    Description:
    H5Tarray_create2 creates a new array datatype object.

    base_type_id is the datatype of every element of the array, i.e., of the number at each position in the array.

    rank is the number of dimensions and the size of each dimension is specified in the array dims. The value of rank is currently limited to H5S_MAX_RANK and must be greater than 0 (zero). All dimension sizes specified in dims must be greater than 0 (zero).

    Parameters:

    Returns:
    Returns a valid datatype identifier if successful; otherwise returns a negative value.

    Fortran90 Interface:
    None.

    History:

    Last modified: 18 August 2010
    Name: H5Tclose
    Signature:
    herr_t H5Tclose( hid_t dtype_id )

    Purpose:
    Releases a datatype.

    Description:
    H5Tclose releases a datatype. Further access through the datatype identifier is illegal. Failure to release a datatype with this call will result in resource leaks.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to release.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tclose_f
    SUBROUTINE h5tclose_f(type_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
                                            ! 0 on success and -1 on failure
    END SUBROUTINE h5tclose_f
        

    Name: H5Tcommit
    Signature:
    herr_t H5Tcommit( hid_t loc_id, const char *name, hid_t dtype_id )

    herr_t H5Tcommit( hid_t loc_id, const char *name, hid_t dtype_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id )

    Purpose:
    Commits a transient datatype, linking it into the file and creating a new named datatype.

    Description:
    H5Tcommit is a macro that is mapped to either H5Tcommit1 or H5Tcommit2, depending on the needs of the application.

    Such macros are provided to facilitate application compatibility. Their use and mappings are fully described in “API Compatibility Macros in HDF5”; we urge you to read that document closely.

    When both the HDF5 Library and the application are built and installed with no specific compatibility flags, H5Tcommit is mapped to the most recent version of the function, currently H5Tcommit2. If the library and/or application is compiled for Release 1.6 emulation, H5Tcommit will be mapped to H5Tcommit1. Function-specific flags are available to override these settings on a function-by-function basis when the application is compiled.

    Specific compile-time compatibility flags and the resulting mappings are as follows:

    Compatibility setting H5Tcommit mapping

    Global settings
    No compatibility flag H5Tcommit2 
    Enable deprecated symbols H5Tcommit2 
    Disable deprecated symbols H5Tcommit2 
    Emulate Release 1.6 interface     H5Tcommit1 

    Function-level macros
    H5Tcommit_vers = 2 H5Tcommit2
    H5Tcommit_vers = 1 H5Tcommit1

    Fortran90 Interface: h5tcommit_f
    SUBROUTINE h5tcommit_f(loc_id, name, type_id, hdferr, &
                           lcpl_id, tcpl_id, tapl_id ) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: loc_id  ! File or group identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name  ! Datatype name within file or group
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
                                            ! 0 on success and -1 on failure
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: lcpl_id 
                                            ! Link creation property list
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: tcpl_id 
                                            ! Datatype creation property list
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: tapl_id 
                                            ! Datatype access property list
    END SUBROUTINE h5tcommit_f
        

    History:
    Release     C
    1.8.0 The function H5Tcommit renamed to H5Tcommit1 and deprecated in this release.
    The macro H5Tcommit and the function H5Tcommit2 introduced in this release.

    Last modified: 3 May 2011
    Name: H5Tcommit1
    Signature:
    herr_t H5Tcommit1( hid_t loc_id, const char * name, hid_t dtype_id )
    Purpose:
    Commits a transient datatype to a file, creating a new named datatype.

    Notice:
    This function is deprecated in favor of the function H5Tcommit2.

    Description:
    H5Tcommit1 commits the transient datatype (not immutable) to a file, turning it into a named datatype.

    The datatype dtype_id is committed as a named datatype at the location loc_id, which is either a file or group identifier, with the name name.

    name can be a relative path based at loc_id or an absolute path from the root of the file. Use of this function requires that any intermediate groups specified in the path already exist.

    As is the case for any object in a group, the length of the name of a named datatype is not limited.

    See H5Tcommit_anon for a discussion of the differences between H5Tcommit and H5Tcommit_anon.

    This function will not accept a datatype that cannot actually hold data. This currently includes compound datatypes with no fields and enumerated datatypes with no members.

    Parameters:

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: See listing under H5Tcommit.

    History:
    Release     C
    1.8.0 The function H5Tcommit renamed to H5Tcommit1 and deprecated in this release.
    1.8.7 Function modified in this release to reject datatypes that will not accomodate actual data, such as a compound datatype with no fields or an enumerated datatype with no members.

    Last modified: 3 May 2011
    Name: H5Tcommit2
    Signature:
    herr_t H5Tcommit2( hid_t loc_id, const char *name, hid_t dtype_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id )

    Purpose:
    Commits a transient datatype, linking it into the file and creating a new named datatype.

    Description:
    H5Tcommit2 saves a transient datatype as an immutable named datatype in a file. The datatype specified by dtype_id is committed to the file with the name name at the location specified by loc_id and with the datatype creation and access property lists tcpl_id and tapl_id, respectively.

    loc_id may be a file identifier, or a group identifier within that file. name may be either an absolute path in the file or a relative path from loc_id naming the newly-commited datatype.

    The link creation property list, lcpl_id, governs creation of the link(s) by which the new named datatype is accessed and the creation of any intermediate groups that may be missing.

    Once commited, this datatype may be used to define the datatype of any other dataset or attribute in the file.

    This function will not accept a datatype that cannot actually hold data. This currently includes compound datatypes with no fields and enumerated datatypes with no members.

    Parameters:
    hid_t loc_id IN: Location identifier
    const char *name     IN: Name given to committed datatype
    hid_t dtype_id IN: Identifier of datatype to be committed and, upon function’s return, identifier for the committed datatype
    hid_t lcpl_id IN: Link creation property list
    hid_t tcpl_id IN: Datatype creation property list
    hid_t tapl_id IN: Datatype access property list

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface:
    See listing under H5Tcommit.

    History:
    Release     C
    1.8.0 Function introduced in this release.
    1.8.7 Function modified in this release to reject datatypes that will not accomodate actual data, such as a compound datatype with no fields or an enumerated datatype with no members.

    Last modified: 26 August 2013
    Name: H5Tcommit_anon
    Signature:
    herr_t H5Tcommit_anon( hid_t loc_id, hid_t dtype_id, hid_t tcpl_id, hid_t tapl_id )

    Purpose:
    Commits a transient datatype to a file, creating a new named datatype, but does not link it into the file structure.

    Description:
    H5Tcommit_anon commits a transient datatype (not immutable) to a file, turning it into a named datatype with the specified creation and property lists. With default property lists, H5P_DEFAULT, H5Tcommit_anon provides similar functionality to that of H5Tcommit, with the differences described below.

    The datatype access property list identifier, tapl_id, is provided for future functionality and is not used at this time. This parameter should always be passed as the value H5P_DEFAULT.

    Note that H5Tcommit_anon does not link this newly-committed datatype into the file. After the H5Tcommit_anon call, the datatype identifier dtype_id must be linked into the HDF5 file structure with H5Olink or it will be deleted from the file when the file is closed.

    The differences between this function and H5Tcommit are as follows:

    This function will not accept a datatype that cannot actually hold data. This currently includes compound datatypes with no fields and enumerated datatypes with no members.

    Parameters:
    hid_t loc_id IN: A file or group identifier specifying the file in which the new named datatype is to be created.
    hid_t dtype_id IN: A datatype identifier.
    hid_t tcpl_id IN: A datatype creation property list identifier.
    (H5P_DEFAULT for the default property list.)
    hid_t tapl_id     IN: A datatype access property list identifier.
    Currently unused; should always be passed as the value H5P_DEFAULT.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tcommit_anon_f
    SUBROUTINE h5tcommit_anon_f(loc_id, dtype_id, hdferr, tcpl_id, tapl_id)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: loc_id ! A file or group identifier specifying 
                                           ! the file in which the new named 
                                           ! datatype is to be created.
      INTEGER(HID_T), INTENT(IN) :: dtype_id  
                                           ! Datatype identifier 
      INTEGER, INTENT(OUT) :: hdferr       ! Error code
                                           ! 0 on success and -1 on failure
    
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: tcpl_id 
                                           ! A datatype creation property 
                                           ! list identifier.
                                           !  H5P_DEFAULT_F = default property list
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: tapl_id 
                                           ! A datatype access property list id
    END SUBROUTINE h5tcommit_anon_f
        

    See Also:
    H5Olink
    H5Tcommit
    History:
    Release     C
    1.8.7 Function modified in this release to reject datatypes that will not accomodate actual data, such as a compound datatype with no fields or an enumerated datatype with no members.
    1.8.0 Function introduced in this release.

    Name: H5Tcommitted
    Signature:
    htri_tH5Tcommitted( hid_t dtype_id )
    Purpose:
    Determines whether a datatype is a named type or a transient type.
    Description:
    H5Tcommitted queries a type to determine whether the type specified by the dtype_id identifier is a named type or a transient type. If this function returns a positive value, then the type is named (that is, it has been committed, perhaps by some other application). Datasets which return committed datatypes with H5Dget_type() are able to share the datatype with other datasets in the same file.
    Parameters:
    Returns:
    When successful, returns a positive value, for TRUE, if the datatype has been committed, or 0 (zero), for FALSE, if the datatype has not been committed. Otherwise returns a negative value.
    Fortran90 Interface: h5tcommitted_f
    SUBROUTINE h5tcommitted_f(dtype_id, committed, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: dtype_id  
                                        ! A datatype identifier
      LOGICAL, INTENT(OUT) :: committed ! .TRUE., if the datatype committed
                                        ! .FALSE., if the datatype not committed.
      INTEGER, INTENT(OUT) :: hdferr    ! Error code
                                        ! 0 on success and -1 on failure
    END SUBROUTINE h5tcommitted_f
    	

    Name: H5Tcompiler_conv
    Signature:
    htri_t H5Tcompiler_conv(hid_t src_id, hid_t dst_id)
    Purpose:
    Check whether the library’s default conversion is hard conversion.
    Description:
    H5Tcompiler_conv finds out whether the library’s conversion function from type src_id to type dst_id is a compiler (hard) conversion. A compiler conversion uses compiler’s casting; a library (soft) conversion uses the library’s own conversion function.
    Parameters:
    Returns:
    Returns TRUE for compiler conversion, FALSE for library conversion, FAIL for the function’s failure.
    Fortran90 Interface: h5tcompiler_conv_f
    SUBROUTINE h5tcompiler_conv_f( src_id, dst_id, flag, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: src_id ! Id for the source datatype.
      INTEGER(HID_T), INTENT(IN) :: dst_id ! Id for the destination datatype.
      LOGICAL, INTENT(OUT) :: flag         !   .TRUE. for compiler conversion, 
                                           !   .FALSE. for library conversion
      INTEGER, INTENT(OUT) :: hdferr       ! Error code:
                                           ! 0 on success and -1 on failure
    END SUBROUTINE h5tcompiler_conv_f
      

    Last modified: 1 February 2013
    Name: H5Tconvert
    Signature:
    herr_t H5Tconvert( hid_t src_type_id, hid_t dest_type_id, size_t nelmts, void *buf, void *background, hid_t plist_id )

    Purpose:
    Converts data from one specified datatype to another.

    Description:
    H5Tconvert converts nelmts elements from a source datatype, specified by src_type_id, to a destination datatype, dest_type_id. The source elements are packed in buf and on return the destination elements will be packed in buf. That is, the conversion is performed in place.

    The optional background buffer is for use with compound datatypes. It is an array of nelmts values for the destination datatype which can then be merged with the converted values to recreate the compound datatype. For instance, background might be an array of structs with the a and b fields already initialized and the conversion of buf supplies the c and d field values.

    The parameter plist_id contains the dataset transfer property list identifier which is passed to the conversion functions. As of Release 1.2, this parameter is only used to pass along the variable-length datatype custom allocation information.

    Programming Note for C++ Developers Using C Functions:

    If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.

    Examples of this kind of routine include callbacks such as H5Pset_elink_cb and H5Pset_type_conv_cb and functions such as H5Tconvert and H5Ewalk2.

    Exiting the routine in its normal fashion allows the HDF5 C Library to clean up its work properly. In other words, if the C++ application jumps out of the routine back to the C++ “catch” statement, the library is not given the opportunity to close any temporary data structures that were set up when the routine was called. The C++ application should save some state as the routine is started so that any problem that occurs might be diagnosed.

    Parameters:
    hid_t src_type_id IN: Identifier for the source datatype.
    hid_t dest_type_id IN: Identifier for the destination datatype.
    size_t nelmts IN: Size of array buf.
    void *buf IN/OUT: Array containing pre- and post-conversion values.
    H5Tconvert will not resize this buffer; it must be large enough to hold the larger of the input and output data.
    void *background     IN: Optional background buffer.
    hid_t plist_id IN: Dataset transfer property list identifier.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran2003 Interface: h5tconvert_f
    Signature:

      SUBROUTINE h5tconvert_f(src_id, dst_id, nelmts, buf, hdferr, background, plist_id)
        INTEGER(HID_T) , INTENT(IN)               :: src_id
        INTEGER(HID_T) , INTENT(IN)               :: dst_id
        INTEGER(SIZE_T), INTENT(IN)               :: nelmts
        TYPE(C_PTR)    , INTENT(INOUT)            :: buf
        INTEGER        , INTENT(OUT)              :: hdferr
        TYPE(C_PTR)    , INTENT(INOUT), OPTIONAL  :: background
        INTEGER(HID_T) , INTENT(IN)   , OPTIONAL  :: plist_id
    

    Inputs:

      src_id     - Identifier for the source datatype.
      dst_id     - Identifier for the destination datatype.
      nelmts     - Size of array buf.
      buf        - Array containing pre-conversion values.
      background - Optional background buffer.
      plist_id   - Dataset transfer property list identifier.
    

    Outputs:

      buf        - Array containing post-conversion values.
      hdferr     - error code:
                     0 on success and -1 on failure
    

    History:
    Release     Change
    1.8.8 Fortran subroutine added.
    1.6.3 In C function, nelmts parameter type changed to size_t.
    1.4.0 In C function, nelmts parameter type changed to hsize_t.

    Last modified: 11 October 2012
    Name: H5Tcopy
    Signature:
    hid_t H5Tcopy( hid_t dtype_id )

    Purpose:
    Copies an existing datatype.

    Description:
    H5Tcopy copies an existing datatype. The returned type is always transient and unlocked.

    The dtype_id argument can be either a datatype identifier, a predefined datatype (defined in H5Tpublic.h), or a dataset identifier. If dtype_id is a dataset identifier instead of a datatype identifier, then this function returns a transient, modifiable datatype which is a copy of the dataset's datatype.

    The datatype identifier returned should be released with H5Tclose or resource leaks will occur.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to copy. Can be a datatype identifier, a predefined datatype (defined in H5Tpublic.h), or a dataset identifier.

    Returns:
    Returns a datatype identifier if successful; otherwise returns a negative value

    See Also:
    If dtype_id is to be a variable-length string datatype, see “Creating variable-length string datatypes.”

    Fortran90 Interface: h5tcopy_f
    SUBROUTINE h5tcopy_f(type_id, new_type_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id      ! Datatype identifier 
      INTEGER(HID_T), INTENT(OUT) :: new_type_id ! Identifier of datatype's copy 
      INTEGER, INTENT(OUT) :: hdferr             ! Error code
                                                 ! 0 on success and -1 on failure
    END SUBROUTINE h5tcopy_f
        

    Last modified: 16 August 2013
    Name: H5Tcreate
    Signature:
    hid_t H5Tcreate( H5T_class_t class, size_tsize )

    Purpose:
    Creates a new datatype.

    Description:
    H5Tcreate creates a new datatype of the specified class with the specified number of bytes. This function is used only with the following datatype classes: Other datatypes, including integer and floating-point datatypes, are typically created by using H5Tcopy to copy and modify a predefined datatype.

    When creating a variable-length string datatype, size must be H5T_VARIABLE; see “Creating variable-length string datatypes.”

    When creating a fixed-length string datatype, size will be the length of the string in bytes. The length of the string in characters will depend on the encoding used; see H5Pset_char_encoding.

    ENUMs created with this function have a signed native integer base datatype. Use H5Tenum_create if a different integer base datatype is required.

    The datatype identifier returned from this function should be released with H5Tclose or resource leaks will result.

    Parameters:
    H5T_class_t class     IN: Class of datatype to create; valid values include:
        H5T_COMPOUND
        H5T_OPAQUE
        H5T_ENUM
        H5T_STRING
    size_t size IN: Size, in bytes, of the datatype being created

    Returns:
    Returns datatype identifier if successful; otherwise returns a negative value.

    See Also:
    H5Pset_char_encoding
    H5Tcopy
    H5Tenum_create
             Creating variable-length string datatypes
    HDF5 Predefined Datatypes

    Fortran90 Interface: h5tcreate_f
    SUBROUTINE h5tcreate_f(class, size, type_id, hdferr) 
      IMPLICIT NONE
      INTEGER, INTENT(IN) :: class             ! Datatype class can be one of
                                               !    H5T_COMPOUND_F
                                               !    H5T_OPAQUE_F
                                               !    H5T_ENUM_F
                                               !    H5T_STRING_F
      INTEGER(SIZE_T), INTENT(IN) :: size      ! Size of the datatype
      INTEGER(HID_T), INTENT(OUT) :: type_id   ! Datatype identifier
      INTEGER, INTENT(OUT) :: hdferr           ! Error code
                                               ! 0 on success and -1 on failure
    END SUBROUTINE h5tcreate_f
        

    History:
    Release     Change
    1.8.8 String datatype capability added to function in this release.

    Last modified: 29 August 2012
    Name: H5Tdecode

    Signature:
    hid_t H5Tdecode (unsigned char *buf)

    Purpose:
    Decode a binary object description of datatype and return a new object handle.

    Description:
    Given an object description of datatype in binary in a buffer, H5Tdecode reconstructs the HDF5 datatype object and returns a new object handle for it. The binary description of the object is encoded by H5Tencode. User is responsible for passing in the right buffer.

    The datatype identifier returned by this function can be released with H5Tclose when the identifier is no longer needed so that resource leaks will not develop.

    Parameters:

    Returns:
    Returns an object identifier (non-negative) if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tdecode_f
    SUBROUTINE h5tdecode_f(buf, obj_id, hdferr)
      IMPLICIT NONE
      CHARACTER(LEN=*), INTENT(IN) :: buf  ! Data space object buffer to be decoded
      INTEGER(HID_T), INTENT(OUT) :: obj_id! Object identifier 
      INTEGER, INTENT(OUT) :: hdferr       ! Error code
                                           ! 0 on success and -1 on failure
    END SUBROUTINE h5tdecode_f
        

    Last modified: 18 August 2010
    Name: H5Tdetect_class
    Signature:
    htri_t H5Tdetect_class( hid_t dtype_id, H5T_class_tdtype_class )

    Purpose:
    Determines whether a datatype contains any datatypes of the given datatype class.

    Description:
    H5Tdetect_class determines whether the datatype specified in dtype_id contains any datatypes of the datatype class specified in dtype_class.

    This function is useful primarily in recursively examining all the fields and/or base types of compound, array, and variable-length datatypes.

    Valid class identifiers are as defined in H5Tget_class.

    Parameters:
    hid_t dtype_id IN: Datatype identifier.
    H5T_class_t dtype_class     IN: Datatype class.

    Returns:
    Returns TRUE or FALSE if successful; otherwise returns a negative value.
    Fortran90 Interface:
    None.

    History:
    Release     C
    1.6.0 Function introduced in this release.

    Name: H5Tencode
    Signature:
    herr_t H5Tencode(hid_t obj_id, unsigned char *buf, size_t *nalloc)
    Purpose:
    Encode a datatype object description into a binary buffer.
    Description:
    Given datatype identifier, H5Tencode converts a data type description into binary form in a buffer. Using this binary form in the buffer, a datatype object can be reconstructed using H5Tdecode to return a new object handle (hid_t) for this datatype.

    A preliminary H5Tencode call can be made to find out the size of the buffer needed. This value is returned as nalloc. That value can then be assigned to nalloc for a second H5Tencode call, which will retrieve the actual encoded object.

    If the library finds out nalloc is not big enough for the object, it simply returns the size of the buffer needed through nalloc without encoding the provided buffer.

    Parameters:
    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tencode_f
    SUBROUTINE h5tencode_f(obj_id, buf, nalloc, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: obj_id ! Identifier of the object to be encoded
      CHARACTER(LEN=*), INTENT(OUT) :: buf ! Buffer object to be encoded into
      INTEGER(SIZE_T), INTENT(INOUT) :: nalloc 
                                           ! The size of the allocated buffer
      INTEGER, INTENT(OUT) :: hdferr       ! Error code
                                           ! 0 on success and -1 on failure
    END SUBROUTINE h5tencode_f
        

    Last modified: 15 August 2013
    Name: H5Tenum_create
    Signature:
    hid_t H5Tenum_create( hid_t dtype_id )

    Purpose:
    Creates a new enumeration datatype.

    Description:
    H5Tenum_create creates a new enumeration datatype based on the specified base datatype, dtype_id, which must be an integer datatype.

    If a particular architecture datatype is required, a little endian or big endian datatype for example, use a native datatype as the base datatype and use H5Tconvert on values as they are read from or written to a dataset.

    Parameters:
    hid_t dtype_id     IN: Datatype identifier for the base datatype.
    Must be an integer datatype.

    Returns:
    Returns the datatype identifier for the new enumeration datatype if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tenum_create_f
    SUBROUTINE h5tenum_create_f(dtype_id, new_type_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: dtype_id      ! Datatype identifier for
                                                  ! the  base datatype
      INTEGER(HID_T), INTENT(OUT) :: new_type_id  ! Datatype identifier for the
                                                  ! new enumeration datatype    
      INTEGER, INTENT(OUT) :: hdferr              ! Error code
    END SUBROUTINE h5tenum_create_f
        

    See Also:
    H5Tenum_insert
    H5Tenum_valueof
    H5Tenum_nameof
    H5Tget_member_value
             H5Tconvert
    H5Tcreate

    Last modified: 29 April 2013
    Name: H5Tenum_insert
    Signature:
    herr_t H5Tenum_insert( hid_t dtype_id, const char *name, void *value )

    Purpose:
    Inserts a new enumeration datatype member.

    Description:
    H5Tenum_insert inserts a new enumeration datatype member into an enumeration datatype.

    dtype_id is the datatype identifier for the enumeration datatype, name is the name of the new member, and value points to the value of the new member.

    name and value must both be unique within dtype_id.

    value points to data which must be of the integer base datatype used when the enumeration datatype was created. If a particular architecture datatype is required, a little endian or big endian datatype for example, use a native datatype as the base datatype and use H5Tconvert on values as they are read from or written to a dataset.

    Parameters:

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tenum_insert_f
    SUBROUTINE h5tenum_insert_f(type_id,  name, value, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name  ! Name of the new member
      INTEGER, INTENT(IN) :: value          ! Value of the new member
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tenum_insert_f
        

    See Also:
    H5Tenum_create
    H5Tenum_valueof
    H5Tenum_nameof
    H5Tget_member_value
    H5Tconvert

    Last modified: 23 April 2013
    Name: H5Tenum_nameof
    Signature:
    herr_t H5Tenum_nameof( hid_t dtype_id, void *value, char *name, size_t size )

    Purpose:
    Returns the symbol name corresponding to a specified member of an enumeration datatype.

    Description:
    H5Tenum_nameof finds the symbol name that corresponds to the specified value of the enumeration datatype dtype_id.

    At most size characters of the symbol name are copied into the name buffer. If the entire symbol name and null terminator do not fit in the name buffer, then as many characters as possible are copied (not null terminated) and the function fails.

    Parameters:

    Returns:
    Returns a non-negative value if successful. Otherwise returns a negative value and, if size allows it, the first character of name is set to NULL.

    Fortran90 Interface: h5tenum_nameof_f
    SUBROUTINE h5tenum_nameof_f(type_id, value, namelen, name, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER, INTENT(IN) :: value           ! Value of the enumeration datatype
      INTEGER(SIZE_T), INTENT(IN) :: namelen ! Length of the name
      CHARACTER(LEN=*), INTENT(OUT) :: name  ! Name of the enumeration datatype
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
    END SUBROUTINE h5tenum_nameof_f
    	

    See Also:
    H5Tenum_create
    H5Tenum_insert
    H5Tenum_valueof
    H5Tget_member_value
    H5Tconvert

    Last modified: 1 May 2013
    Name: H5Tenum_valueof
    Signature:
    herr_t H5Tenum_valueof( hid_t dtype_id, char *name, void *value )

    Purpose:
    Returns the value corresponding to a specified member of an enumeration datatype.

    Description:
    H5Tenum_valueof finds the value that corresponds to the specified name of the enumeration datatype dtype_id.

    Values returned in value will be of the enumerated type’s base type, that is, the datatype used by H5Tenum_create when the enumerated type was created.

    The value buffer must be at least large enough to hold a value of that base type. If the size is unknown, you can determine it with H5Tget_size(dtype_id), where dtype_id is set to the base type.

    Parameters:
    hid_t dtype_id IN: Enumeration datatype identifier.
    const char *name     IN: Symbol name of the enumeration datatype.
    void *value OUT: Buffer for output of the value of the enumeration datatype.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tenum_valueof_f
    SUBROUTINE h5tenum_valueof_f(type_id,  name, value, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name  ! Name of the enumeration datatype
      INTEGER, INTENT(OUT) :: value         ! Value of the enumeration datatype
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tenum_valueof_f
        

    See Also:
    H5Tenum_create
    H5Tenum_insert
    H5Tenum_nameof
    H5Tget_member_value
    H5Tconvert

    Last modified: 18 August 2010
    Name: H5Tequal
    Signature:
    htri_t H5Tequal( hid_t dtype_id1, hid_t dtype_id2 )

    Purpose:
    Determines whether two datatype identifiers refer to the same datatype.

    Description:
    H5Tequal determines whether two datatype identifiers refer to the same datatype.

    Parameters:
    hid_t dtype_id1     IN: Identifier of datatype to compare.
    hid_t dtype_id2 IN: Identifier of datatype to compare.

    Returns:
    When successful, returns a positive value, for TRUE, if the datatype identifiers refer to the same datatype, or 0 (zero), for FALSE. Otherwise returns a negative value.

    Fortran90 Interface: h5tequal_f
    SUBROUTINE h5tequal_f(type1_id, type2_id, flag, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type1_id ! Datatype identifier 
      INTEGER(HID_T), INTENT(IN) :: type2_id ! Datatype identifier 
      LOGICAL, INTENT(OUT) :: flag           ! TRUE/FALSE flag to indicate 
                                             ! if two datatypes are equal
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
    END SUBROUTINE h5tequal_f
        

    Name: H5Tfind
    Signature:
    H5T_conv_t H5Tfind(hid_t src_id, hid_t dst_id, H5T_cdata_t **pcdata )
    Purpose:
    Finds a conversion function.
    Description:
    H5Tfind finds a conversion function that can handle a conversion from type src_id to type dst_id. The pcdata argument is a pointer to a pointer to type conversion data which was created and initialized by the soft type conversion function of this path when the conversion function was installed on the path.
    Parameters:
    Returns:
    Returns a pointer to a suitable conversion function if successful. Otherwise returns NULL.
    Fortran90 Interface:
    None.

    Name: H5Tget_array_dims
    Signatures:
    int H5Tget_array_dims( hid_t adtype_id, hsize_t dims[], int perm[] ) [1]
    int H5Tget_array_dims( hid_t adtype_id, hsize_t dims[] ) [2]

    Purpose:
    Retrieves sizes of array dimensions.

    Description:
    H5Tget_array_dims is a macro that is mapped to either H5Tget_array_dims1 or H5Tget_array_dims2, depending on the needs of the application.

    Such macros are provided to facilitate application compatibility. For example:

    Macro use and mappings are fully described in “API Compatibility Macros in HDF5”; we urge you to read that document closely.

    When both the HDF5 Library and the application are built and installed with no specific compatibility flags, H5Tget_array_dims is mapped to the most recent version of the function, currently H5Tget_array_dims2. If the library and/or application is compiled for Release 1.6 emulation, H5Tget_array_dims will be mapped to H5Tget_array_dims1. Function-specific flags are available to override these settings on a function-by-function basis when the application is compiled.

    Specific compile-time compatibility flags and the resulting mappings are as follows:

    Compatibility setting H5Tget_array_dims mapping

    Global settings
    No compatibility flag H5Tget_array_dims2 
    Enable deprecated symbols H5Tget_array_dims2 
    Disable deprecated symbols H5Tget_array_dims2 
    Emulate Release 1.6 interface H5Tget_array_dims1 

    Function-level macros
    H5Tget_array_dims_vers = 2     H5Tget_array_dims2
    H5Tget_array_dims_vers = 1 H5Tget_array_dims1

    Interface history:   Signature [1] above is the original H5Tget_array_dims interface and the only interface available prior to HDF5 Release 1.8.0. This signature and the corresponding function are now deprecated but will remain directly callable as H5Tget_array_dims1.

    Signature [2] above was introduced with HDF5 Release 1.8.0 and is the recommended and default interface. It is directly callable as H5Tget_array_dims2.

    See “API Compatibility Macros in HDF5” for circumstances under which either of these functions might not be available in an installed instance of the HDF5 Library.

    Fortran90 Interface: h5tarray_create_f
    SUBROUTINE h5tarray_create_f(base_id, rank, dims, type_id, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: base_id   ! Identifier of array base datatype
      INTEGER, INTENT(IN)        ::  rank     ! Rank of the array
      INTEGER(HSIZE_T), DIMENSION(*), INTENT(IN) :: dims 
                                              ! Sizes of each array dimension
      INTEGER(HID_T), INTENT(OUT) :: type_id  ! Identifier of the array datatype
      INTEGER, INTENT(OUT)        :: hdferr   ! Error code
    END SUBROUTINE h5tarray_create_f
    	

    History:
    Release     C
    1.8.0 The function H5Tget_array_dims renamed to H5Tget_array_dims1 and deprecated in this release.
    The macro H5Tget_array_dims and the function H5Tget_array_dims2 introduced in this release.

    Name: H5Tget_array_dims1
    Signature:
    int H5Tget_array_dims1( hid_t adtype_id, hsize_t dims[], int perm[] )

    Purpose:
    Retrieves sizes of array dimensions.

    Notice:
    This function is renamed from H5Tget_array_dims and deprecated in favor of the function H5Tget_array_dims2 or the new macro H5Tget_array_dims.

    Description:
    H5Tget_array_dims1 returns the sizes of the dimensions and the dimension permutations of the specified array datatype object.

    The sizes of the dimensions are returned in the array dims.

    The parameter perm is not used.

    Parameters:

    Returns:
    Returns the non-negative number of dimensions of the array type if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_array_dims_f
    SUBROUTINE h5tget_array_dims_f(type_id, dims, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id      ! Identifier of the array datatype
      INTEGER(HSIZE_T), DIMENSION(*), INTENT(OUT) ::  dims 
                                                 ! Buffer to store array datatype
      INTEGER, INTENT(OUT)  :: hdferr            ! Error code
    END SUBROUTINE h5tget_array_dims_f
    	

    History:

    Name: H5Tget_array_dims2
    Signature:
    int H5Tget_array_dims2( hid_t adtype_id, hsize_t dims[] )

    Purpose:
    Retrieves sizes of array dimensions.

    Description:
    H5Tget_array_dims2 returns the sizes of the dimensions of the specified array datatype object.

    The sizes of the dimensions are returned in the array dims.

    Parameters:

    Returns:
    Returns the non-negative number of dimensions of the array type if successful; otherwise returns a negative value.

    Fortran90 Interface:
    None.

    History:

    Name: H5Tget_array_ndims
    Signature:
    int H5Tget_array_ndims( hid_t adtype_id )
    Purpose:
    Returns the rank of an array datatype.
    Description:
    H5Tget_array_ndims returns the rank, the number of dimensions, of an array datatype object.
    Parameters:
    Returns:
    Returns the rank of the array if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tget_array_ndims_f
    SUBROUTINE h5tget_array_ndims_f(type_id, ndims, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Identifier of the array datatype
      INTEGER, INTENT(OUT)       ::  ndims   ! Number of array dimensions
      INTEGER, INTENT(OUT)       :: hdferr   ! Error code
    END SUBROUTINE h5tget_array_ndims_f
    	
    History:

    Last modified: 18 August 2010
    Name: H5Tget_class
    Signature:
    H5T_class_t H5Tget_class( hid_t dtype_id )

    Purpose:
    Returns the datatype class identifier.

    Description:
    H5Tget_class returns the datatype class identifier.

    Valid class identifiers, as defined in H5Tpublic.h, are:

    Note that the library returns H5T_STRING for both fixed-length and variable-length strings.

    Unsupported datatype: The time datatype class, H5T_TIME, is not supported. If H5T_TIME is used, the resulting data will be readable and modifiable only on the originating computing platform; it will not be portable to other platforms.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns datatype class identifier if successful; otherwise H5T_NO_CLASS (-1).

    Fortran90 Interface: h5tget_class_f
    SUBROUTINE h5tget_class_f(type_id, class, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER, INTENT(OUT) :: class          ! Datatype class, possible values are:
                                             !    H5T_NO_CLASS_F 
                                             !    H5T_INTEGER_F 
                                             !    H5T_FLOAT_F
    
                                             !    H5T_STRING_F
                                             !    H5T_BITFIELD_F
                                             !    H5T_OPAQUE_F
                                             !    H5T_COMPOUND_F
                                             !    H5T_REFERENCE_F
                                             !    H5T_ENUM_F
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_class_f
        

    Name: H5Tget_create_plist
    Signature:
    hid_t H5Tget_create_plist( hid_t dtype_id )

    Purpose:
    Returns a copy of a datatype creation property list.

    Description:
    H5Tget_create_plist returns a property list identifier for the datatype creation property list associated with the datatype specified by dtype_id.

    The creation property list identifier should be released with H5Pclose.

    Parameter:
    hid_t dtype_id     IN: Datatype identifier.

    Returns:
    Returns a datatype property list identifier if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_create_plist_f
    SUBROUTINE h5tget_create_plist_f(dtype_id, dtpl_id, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: dtype_id ! Datatype identifier
      INTEGER(HID_T), INTENT(OUT) :: dtpl_id ! Datatype property list identifier.
      INTEGER, INTENT(OUT) :: hdferr         ! Error code:
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_create_plist_f 
        

    History:
    Release     C
    1.8.0 Function introduced in this release.

    Last modified: 18 August 2010
    Name: H5Tget_cset
    Signature:
    H5T_cset_t H5Tget_cset( hid_t dtype_id )

    Purpose:
    Retrieves the character set type of a string datatype.

    Description:
    H5Tget_cset retrieves the character set type of a string datatype. Valid character set types are:
             H5T_CSET_ASCII   (0)      Character set is US ASCII.
      H5T_CSET_UTF8   (1)   Character set is UTF-8, enabling Unicode encoding.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a valid character set type if successful; otherwise H5T_CSET_ERROR (-1).

    Fortran90 Interface: h5tget_cset_f
    SUBROUTINE h5tget_cset_f(type_id, cset, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: cset          ! Character set type of a string 
                                            ! datatype 
                                            ! Possible values are:
                                            !    H5T_CSET_ASCII_F = 0
                                            !    H5T_CSET_UTF8_F = 1
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_cset_f
        

    History:
    Release     Change
    1.8.0 UTF-8 Unicode encoding introduced in this release.

    Last modified: 18 August 2010
    Name: H5Tget_ebias
    Signature:
    size_t H5Tget_ebias( hid_t dtype_id )

    Purpose:
    Retrieves the exponent bias of a floating-point type.

    Description:
    H5Tget_ebias retrieves the exponent bias of a floating-point type.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns the bias if successful; otherwise 0.

    Fortran90 Interface: h5tget_ebias_f
    SUBROUTINE h5tget_ebias_f(type_id, ebias, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(OUT) :: ebias ! Datatype exponent bias 
                                            ! of a floating-point type
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_ebias_f
        

    Name: H5Tget_fields
    Signature:
    herr_t H5Tget_fields( hid_t dtype_id, size_t *spos, size_t *epos, size_t *esize, size_t *mpos, size_t *msize )
    Purpose:
    Retrieves floating point datatype bit field information.
    Description:
    H5Tget_fields retrieves information about the locations of the various bit fields of a floating point datatype. The field positions are bit positions in the significant region of the datatype. Bits are numbered with the least significant bit number zero. Any (or even all) of the arguments can be null pointers.
    Parameters:
    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tget_fields_f
    SUBROUTINE h5tget_fields_f(type_id, spos, epos, esize, mpos, msize, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier
      INTEGER(SIZE_T), INTENT(OUT) :: spos  ! sign bit-position 
      INTEGER(SIZE_T), INTENT(OUT) :: epos  ! exponent bit-position 
      INTEGER(SIZE_T), INTENT(OUT) :: esize ! size of exponent in bits
      INTEGER(SIZE_T), INTENT(OUT) :: mpos  ! mantissa bit-position 
      INTEGER(SIZE_T), INTENT(OUT) :: msize ! size of mantissa in bits
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_fields_f
    	

    Last modified: 18 August 2010
    Name: H5Tget_inpad
    Signature:
    H5T_pad_t H5Tget_inpad( hid_t dtype_id )

    Purpose:
    Retrieves the internal padding type for unused bits in floating-point datatypes.

    Description:
    H5Tget_inpad retrieves the internal padding type for unused bits in floating-point datatypes. Valid padding types are:

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a valid padding type if successful; otherwise H5T_PAD_ERROR (-1).

    Fortran90 Interface: h5tget_inpad_f
    SUBROUTINE h5tget_inpad_f(type_id, padtype, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: padtype       ! Padding type for unused bits 
                                            ! in floating-point datatypes
                                            ! Possible values of padding type are:
                                            !     H5T_PAD_ZERO_F = 0
                                            !     H5T_PAD_ONE_F = 1
                                            !     H5T_PAD_BACKGROUND_F = 2
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_inpad_f
        

    Name: H5Tget_member_class
    Signature:
    H5T_class_t H5Tget_member_class( hid_t cdtype_id, unsigned member_no )
    Purpose:
    Returns datatype class of compound datatype member.
    Description:
    Given a compound datatype, cdtype_id, the function H5Tget_member_class returns the datatype class of the compound datatype member specified by member_no.

    Valid class identifiers are as defined in H5Tget_class.

    Parameters:
    Returns:
    Returns the datatype class, a non-negative value, if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tget_member_class_f
    SUBROUTINE h5tget_member_class_f(type_id, member_no, class, hdferr) 
      INTEGER(HID_T), INTENT(IN) :: type_id       ! Datatype identifier 
      INTEGER, INTENT(IN) :: member_no            ! Member number
      INTEGER, INTENT(OUT) :: class               ! Member class
      INTEGER, INTENT(OUT) :: hdferr              ! Error code
    END SUBROUTINE h5tget_member_class_f
            
    History:

    Last modified: 18 August 2010
    Name: H5Tget_member_index
    Signature:
    int H5Tget_member_index( hid_t dtype_id, const char * field_name )

    Purpose:
    Retrieves the index of a compound or enumeration datatype member.

    Description:
    H5Tget_member_index retrieves the index of a field of a compound datatype or an element of an enumeration datatype.

    The name of the target field or element is specified in field_name.

    Fields are stored in no particular order with index values of 0 through N-1, where N is the value returned by H5Tget_nmembers.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to query.
    const char * field_name     IN: Name of the field or member whose index is to be retrieved.

    Returns:
    Returns a valid field or member index if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_member_index_f
    SUBROUTINE h5tget_member_index_f(type_id, name, index, hdferr) 
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name   ! Member name
      INTEGER, INTENT(OUT) :: index          ! Member index
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
    END SUBROUTINE h5tget_member_index_f
        

    History:
    Release     C      Fortran90
    1.4.5     Function introduced in this release.
    1.4.4 Function introduced in this release.    

    Last modified: 18 August 2010
    Name: H5Tget_member_name
    Signature:
    char * H5Tget_member_name( hid_t dtype_id, unsigned field_idx )

    Purpose:
    Retrieves the name of a compound or enumeration datatype member.

    Description:
    H5Tget_member_name retrieves the name of a field of a compound datatype or an element of an enumeration datatype.

    The index of the target field or element is specified in field_idx. Compound datatype fields and enumeration datatype elements are stored in no particular order with index values of 0 through N-1, where N is the value returned by H5Tget_nmembers.

    A buffer to receive the name of the field is allocated with malloc() and the caller is responsible for freeing the memory used.

    Parameters:
    hid_t tdype_id     IN: Identifier of datatype to query.
    unsigned field_idx    IN: Zero-based index of the field or element whose name is to be retrieved.

    Returns:
    Returns a valid pointer to a string allocated with malloc() if successful; otherwise returns NULL.

    Fortran90 Interface: h5tget_member_name_f
    SUBROUTINE h5tget_member_name_f(type_id,index, member_name,  namelen, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id        ! Datatype identifier 
      INTEGER, INTENT(IN) :: index                 ! Field index (0-based) of 
                                                   ! the field name to retrieve 
      CHARACTER(LEN=*), INTENT(OUT) :: member_name ! Name of a field of
                                                   ! a compound datatype 
      INTEGER, INTENT(OUT) :: namelen              ! Length of the name 
      INTEGER, INTENT(OUT) :: hdferr               ! Error code
    END SUBROUTINE h5tget_member_name_f
        

    History:
    Release     C
    1.6.4 membno parameter type changed to unsigned.

    Last modified: 18 August 2010
    Name: H5Tget_member_offset
    Signature:
    size_t H5Tget_member_offset( hid_t dtype_id, unsigned memb_no )

    Purpose:
    Retrieves the offset of a field of a compound datatype.

    Description:
    H5Tget_member_offset retrieves the byte offset of the beginning of a field within a compound datatype with respect to the beginning of the compound datatype datum.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.
    unsigned memb_no IN: Number of the field whose offset is requested.

    Returns:
    Returns the byte offset of the field if successful; otherwise returns 0 (zero). Note that zero is a valid offset and that this function will fail only if a call to H5Tget_member_class() fails with the same arguments.

    Fortran90 Interface: h5tget_member_offset_f
    SUBROUTINE h5tget_member_offset_f(type_id, member_no, offset, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id    ! Datatype identifier 
      INTEGER, INTENT(IN) :: member_no         ! Number of the field  
                                               ! whose offset is requested
      INTEGER(SIZE_T), INTENT(OUT) :: offset   ! Byte offset of the the 
                                               ! beginning of the field
      INTEGER, INTENT(OUT) :: hdferr           ! Error code
    END SUBROUTINE h5tget_member_offset_f
        

    History:
    Release     C
    1.6.4 membno parameter type changed to unsigned.

    Last modified: 18 August 2010
    Name: H5Tget_member_type
    Signature:
    hid_t H5Tget_member_type( hid_t dtype_id, unsigned field_idx )

    Purpose:
    Returns the datatype of the specified member.

    Description:
    H5Tget_member_type returns the datatype of the specified member. The caller should invoke H5Tclose() to release resources associated with the type.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.
    unsigned field_idx    IN: Field index (0-based) of the field type to retrieve.

    Returns:
    Returns the identifier of a copy of the datatype of the field if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_member_type_f
    SUBROUTINE h5tget_member_type_f(type_id,  field_idx, datatype, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id   ! Datatype identifier 
      INTEGER, INTENT(IN) :: field_idx        ! Field index (0-based) of the 
                                              ! field type to retrieve
      INTEGER(HID_T), INTENT(OUT) :: datatype ! Identifier of a copy of 
                                              ! the datatype of the field 
      INTEGER, INTENT(OUT) :: hdferr          ! Error code
    END SUBROUTINE h5tget_member_type_f
        

    History:
    Release     C
    1.6.4 membno parameter type changed to unsigned.

    Last modified: 1 May 2013
    Name: H5Tget_member_value
    Signature:
    herr_t H5Tget_member_value( hid_t dtype_id, unsigned memb_no, void *value )

    Purpose:
    Returns the value of an enumeration datatype member.

    Description:
    H5Tget_member_value returns the value of the enumeration datatype member memb_no.

    The member value is returned in a user-supplied buffer pointed to by value. Values returned in value will be of the enumerated type’s base type, that is, the datatype used by H5Tenum_create when the enumerated type was created.

    The value buffer must be at least large enough to hold a value of that base type. If the size is unknown, you can determine it with H5Tget_size(dtype_id), where dtype_id is set to the base type.

    Parameters:

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_member_value_f
    SUBROUTINE h5tget_member_value_f(type_id,  member_no, value, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(IN) :: member_no      ! Number of the enumeration 
                                            ! datatype member
      INTEGER, INTENT(OUT) :: value         ! Value of the enumeration datatype
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_member_value_f
        

    See Also:
    H5Tenum_create
    H5Tenum_insert
    H5Tenum_valueof
    H5Tenum_nameof
    H5Tconvert

    History:
    Release     C
    1.6.4 membno parameter type changed to unsigned.

    Last modified: 18 August 2010
    Name: H5Tget_native_type
    Signature:
    hid_t H5Tget_native_type( hid_t dtype_id, H5T_direction_t direction )

    Purpose:
    Returns the native datatype of a specified datatype.

    Description:
    H5Tget_native_type returns the equivalent native datatype for the datatype specified in dtype_id.

    H5Tget_native_type is a high-level function designed primarily to facilitate use of the H5Dread function, for which users otherwise must undertake a multi-step process to determine the native datatype of a dataset prior to reading it into memory. This function can be used for the following purposes:

    For example, if dtype_id is a compound datatype, the returned datatype identifier will be for a similar compound datatype with each element converted to the corresponding native datatype; nested compound datatypes will be unwound. If dtype_id is an array, the returned datatype identifier will be for the native datatype of a single array element.

    H5Tget_native_type selects the first matching native datatype from the following list:

            H5T_NATIVE_CHAR         
            H5T_NATIVE_SHORT        
            H5T_NATIVE_INT          
            H5T_NATIVE_LONG         
            H5T_NATIVE_LLONG        
    
            H5T_NATIVE_UCHAR
            H5T_NATIVE_USHORT
            H5T_NATIVE_UINT
            H5T_NATIVE_ULONG
            H5T_NATIVE_ULLONG
    
            H5T_NATIVE_FLOAT
            H5T_NATIVE_DOUBLE
            H5T_NATIVE_LDOUBLE
    
            H5T_NATIVE_B8
            H5T_NATIVE_B16
            H5T_NATIVE_B32
            H5T_NATIVE_B64

    The direction parameter indicates the order in which the library searches for a native datatype match. Valid values for direction are as follows:
         H5T_DIR_ASCEND Searches the above list in ascending size of the datatype,
    i.e., from top to bottom. (Default)
      H5T_DIR_DESCEND   Searches the above list in descending size of the datatype,
    i.e., from bottom to top.

    H5Tget_native_type is designed primarily for use with integer, floating point, and bitfield datatypes. String, time, opaque, and reference datatypes are returned as a copy of dtype_id. See above for compound, array, enumerated, and variable-length datatypes.

    The identifier returned by H5Tget_native_type should eventually be closed by calling H5Tclose to release resources.

    Parameters:
    hid_t dtype_id IN: Datatype identifier for the dataset datatype.
    H5T_direction_t direction     IN: Direction of search.

    Returns:
    Returns the native datatype identifier for the specified dataset datatype if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_native_type_f
    SUBROUTINE h5tget_native_type_f(dtype_id, direction, native_dtype_id, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: dtype_id  
                                        ! Datatype identifier
      INTEGER, INTENT(IN) :: direction  ! Direction of search:
                                        ! H5T_DIR_ASCEND_F = 1 in inscendent order
                                        ! H5T_DIR_DESCEND_F= 2 in descendent order
      INTEGER(HID_T), INTENT(OUT) :: native_dtype_id  
                                        ! The native datatype identifier
      INTEGER, INTENT(OUT) :: hdferr    ! Error code:
                                        ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_native_type_f
            

    History:
    Release     C
    1.6.0 Function introduced in this release.

    Last modified: 18 August 2010
    Name: H5Tget_nmembers
    Signature:
    int H5Tget_nmembers( hid_t dtype_id )

    Purpose:
    Retrieves the number of elements in a compound or enumeration datatype.

    Description:
    H5Tget_nmembers retrieves the number of fields in a compound datatype or the number of members of an enumeration datatype.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns the number of elements if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_nmembers_f
    SUBROUTINE h5tget_nmembers_f(type_id, num_members, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: num_members   ! Number of fields in a 
                                            ! compound datatype 
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_nmembers_f
        

    Last modified: 18 August 2010
    Name: H5Tget_norm
    Signature:
    H5T_norm_t H5Tget_norm( hid_t dtype_id )

    Purpose:
    Retrieves mantissa normalization of a floating-point datatype.

    Description:
    H5Tget_norm retrieves the mantissa normalization of a floating-point datatype. Valid normalization types are:

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a valid normalization type if successful; otherwise H5T_NORM_ERROR (-1).

    Fortran90 Interface: h5tget_norm_f
    SUBROUTINE h5tget_norm_f(type_id, norm, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  
                                     ! Datatype identifier 
      INTEGER, INTENT(OUT) :: norm   ! Mantissa normalization of a 
                                     ! floating-point datatype
                                     ! Valid normalization types are:
                                     !    H5T_NORM_IMPLIED_F(0) 
                                     !        MSB of mantissa is not 
                                     !        stored, always 1
                                     !    H5T_NORM_MSBSET_F(1) 
                                     !        MSB of mantissa is always 1 
                                     !    H5T_NORM_NONE_F(2) 
                                     !        Mantissa is not normalized
      INTEGER, INTENT(OUT) :: hdferr ! Error code
    END SUBROUTINE h5tget_norm_f
        

    Last modified: 18 August 2010
    Name: H5Tget_offset
    Signature:
    int H5Tget_offset( hid_t dtype_id )

    Purpose:
    Retrieves the bit offset of the first significant bit.

    Description:
    H5Tget_offset retrieves the bit offset of the first significant bit. The significant bits of an atomic datum can be offset from the beginning of the memory for that datum by an amount of padding. The `offset' property specifies the number of bits of padding that appear to the "right of" the value. That is, if we have a 32-bit datum with 16-bits of precision having the value 0x1122 then it will be laid out in memory as (from small byte address toward larger byte addresses):

    Byte Position Big-Endian Offset=0 Big-Endian Offset=16 Little-Endian Offset=0 Little-Endian Offset=16
    0: [ pad] [0x11] [0x22] [ pad]
    1: [ pad] [0x22] [0x11] [ pad]
    2: [0x11] [ pad] [ pad] [0x22]
    3: [0x22] [ pad] [ pad] [0x11]

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns an offset value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_offset_f
    SUBROUTINE h5tget_offset_f(type_id, offset, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(OUT) :: offset ! Datatype bit offset of the
                                             ! first significant bit
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_offset_f
        

    Last modified: 24 September 2010
    Name: H5Tget_order
    Signature:
    H5T_order_t H5Tget_order( hid_t dtype_id )

    Purpose:
    Returns the byte order of an atomic datatype.

    Description:
    H5Tget_order returns the byte order of an atomic datatype.

    Possible return values are:

    Members of a compound datatype need not have the same byte order. If members of a compound datatype have more than one of little endian, big endian, or VAX byte order, H5Tget_order will return H5T_ORDER_MIXED for the compound datatype. A byte order of H5T_ORDER_NONE will, however, be ignored; for example, if one or more members of a compound datatype have byte order H5T_ORDER_NONE but all other members have byte order H5T_ORDER_LE, H5Tget_order will return H5T_ORDER_LE for the compound datatype.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a byte order constant if successful; otherwise H5T_ORDER_ERROR (-1).

    Fortran90 Interface: h5tget_order_f
    SUBROUTINE h5tget_order_f(type_id, order, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: order         ! Datatype byte order 
                                            ! Possible values are:
                                            !    H5T_ORDER_LE_F 
                                            !    H5T_ORDER_BE_F 
                                            !    H5T_ORDER_VAX_F  
                                            !    H5T_ORDER_MIXED_F  
                                            !      (not implemented)
                                            !    H5T_ORDER_NONE_F  
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
                                            ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_order_f
        

    History:
    Release     Change
    1.8.6 Function modified to work with all datatypes.
    H5T_ORDER_MIXED added to H5T_order_t.

    Name: H5Tget_pad
    Signature:
    herr_t H5Tget_pad( hid_t dtype_id, H5T_pad_t * lsb, H5T_pad_t * msb )
    Purpose:
    Retrieves the padding type of the least and most-significant bit padding.
    Description:
    H5Tget_pad retrieves the padding type of the least and most-significant bit padding. Valid types are:
    Parameters:
    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tget_pad_f
    SUBROUTINE h5tget_pad_f(type_id, lsbpad, msbpad, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(OUT) :: lsbpad        ! Padding type of the  
                                            ! least significant bit
      INTEGER, INTENT(OUT) :: msbpad        ! Padding type of the 
                                            ! most significant bit
                                            ! Possible values of 
                                            ! padding type are:
                                            !    H5T_PAD_ZERO_F = 0
                                            !    H5T_PAD_ONE_F = 1
                                            !    H5T_PAD_BACKGROUND_F = 2
                                            !    H5T_PAD_ERROR_F = -1
                                            !    H5T_PAD_NPAD_F = 3
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tget_pad_f
    	

    Last modified: 12 August 2011
    Name: H5Tget_precision

    Signature:
    size_t H5Tget_precision( hid_t dtype_id )

    Purpose:
    Returns the precision of an atomic datatype.

    Description:
    H5Tget_precision returns the precision of an atomic datatype. The precision is the number of significant bits which, unless padding is present, is 8 times larger than the value returned by H5Tget_size.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns the number of significant bits if successful; otherwise 0.

    Fortran90 Interface: h5tget_precision_f
    SUBROUTINE h5tget_precision_f(type_id, precision, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id     ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(OUT) :: precision ! Datatype precision
      INTEGER, INTENT(OUT) :: hdferr            ! Error code
    END SUBROUTINE h5tget_precision_f
        

    Last modified: 18 August 2010
    Name: H5Tget_sign
    Signature:
    H5T_sign_t H5Tget_sign( hid_t dtype_id )

    Purpose:
    Retrieves the sign type for an integer type.

    Description:
    H5Tget_sign retrieves the sign type for an integer type. Valid types are:

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a valid sign type if successful; otherwise H5T_SGN_ERROR (-1).

    Fortran90 Interface: h5tget_sign_f
    SUBROUTINE h5tget_sign_f(type_id, sign, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER, INTENT(OUT) :: sign           ! Sign type for an integer type
                                             ! Possible values are:
                                             !    Unsigned integer type 
                                             !        H5T_SGN_NONE_F = 0
                                             !    Two's complement signed 
                                             !        integer type
                                             !        H5T_SGN_2_F = 1
                                             !    or error value
                                             !         H5T_SGN_ERROR_F = -1 
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
    END SUBROUTINE h5tget_sign_f
        

    Last modified: 17 July 2014
    Name: H5Tget_size
    Signature:
    size_t H5Tget_size( hid_t dtype_id )

    Purpose:
    Returns the size of a datatype.

    Description:
    H5Tget_size returns the size of a datatype in bytes.

    For atomic datatypes, array datatypes, compound datatypes, and other datatypes of a constant size, the returned value is the size of the actual datatype in bytes.

    For variable-length string datatypes (see “Creating variable-length string datatypes”), the returned value is the size of the pointer to the actual string, or sizeof(char *). This function does not return the size of actual variable-length string data.

    For variable-length sequence datatypes (see H5Tvlen_create), the returned value is the size of the hvl_t struct, or sizeof(hvl_t). The hvl_t struct contains a pointer to the actual data and a size value. This function does not return the size of actual variable-length sequence data.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns the size of the datatype in bytes if successful; otherwise 0.

    Fortran90 Interface: h5tget_size_f
    SUBROUTINE h5tget_size_f(type_id, size, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(OUT) :: size  ! Datatype size
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
                                            ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_size_f
        

    Last modified: 15 April 2013
    Name: H5Tget_strpad
    Signature:
    H5T_str_t H5Tget_strpad( hid_t dtype_id )

    Purpose:
    Retrieves the type of padding used for a string datatype.

    Description:
    H5Tget_strpad retrieves the type of padding used for a string datatype.

    The string padding type is set with H5Tset_strpad and valid settings are described in that entry.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to query.

    Returns:
    Returns a valid string storage mechanism if successful; otherwise H5T_STR_ERROR (-1).

    Fortran90 Interface: h5tget_strpad_f
    SUBROUTINE h5tget_strpad_f(type_id, strpad, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id    
                                      ! Datatype identifier 
      INTEGER, INTENT(OUT) :: strpad  ! String padding method for a string datatype 
                                      ! Possible values of padding type are:
                                      !    Pad with zeros (as C does): 
                                      !        H5T_STR_NULLPAD_F(0) 
                                      !    Pad with spaces (as FORTRAN does): 
                                      !        H5T_STR_SPACEPAD_F(1)
      INTEGER, INTENT(OUT) :: hdferr  ! Error code
                                      ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_strpad_f
        

    Last modified: 29 August 2012
    Name: H5Tget_super

    Signature:
    hid_t H5Tget_super( hid_t dtype_id )

    Purpose:
    Returns the base datatype from which a datatype is derived.

    Description:
    H5Tget_super returns the base datatype from which the datatype dtype_id is derived.

    In the case of an enumeration type, the return value is an integer type.

    The datatype identifier returned by this function can be released with H5Tclose when the identifier is no longer needed so that resource leaks will not develop.

    Parameters:
    hid_t dtype_id     IN: Datatype identifier for the derived datatype.

    Returns:
    Returns the datatype identifier for the base datatype if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tget_super_f
    SUBROUTINE h5tget_super_f(type_id, base_type_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER(HID_T), INTENT(OUT) :: type_id ! Base datatype identifier 
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_super_f
        

    Last modified: 18 August 2010
    Name: H5Tget_tag
    Signature:
    char *H5Tget_tag( hid_t dtype_id )

    Purpose:
    Gets the tag associated with an opaque datatype.

    Description:
    H5Tget_tag returns the tag associated with the opaque datatype dtype_id.

    The tag is returned via a pointer to an allocated string, which the caller must free.

    Parameters:
    hid_t dtype_id     IN: Datatype identifier for the opaque datatype.

    Returns:
    Returns a pointer to an allocated string if successful; otherwise returns NULL.

    Fortran90 Interface: h5tget_tag_f
    SUBROUTINE h5tget_tag_f(type_id, tag,taglen, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(OUT) :: tag   ! Unique ASCII string with which the
                                             ! opaque datatype is to be tagged
      INTEGER, INTENT(OUT) :: taglen         ! Length of tag 
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tget_tag_f
        

    Last modified: 18 August 2010
    Name: H5Tinsert
    Signature:
    herr_t H5Tinsert( hid_t dtype_id, const char * name, size_t offset, hid_t field_id )

    Purpose:
    Adds a new member to a compound datatype.

    Description:
    H5Tinsert adds another member to the compound datatype dtype_id. The new member has a name which must be unique within the compound datatype. The offset argument defines the start of the member in an instance of the compound datatype, and field_id is the datatype identifier of the new member.

    Note: Members of a compound datatype do not have to be atomic datatypes; a compound datatype can have a member which is a compound datatype.

    Parameters:
    hid_t dtype_id IN: Identifier of compound datatype to modify.
    const char * name     IN: Name of the field to insert.
    size_t offset IN: Offset in memory structure of the field to insert.
    hid_t field_id IN: Datatype identifier of the field to insert.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tinsert_f
    SUBROUTINE h5tinsert_f(type_id,  name, offset, field_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name   ! Name of the field to insert
      INTEGER(SIZE_T), INTENT(IN) :: offset  ! Offset in memory structure 
                                             ! of the field to insert
      INTEGER(HID_T), INTENT(IN) :: field_id ! Datatype identifier of the 
                                             ! new member
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tinsert_f
        

    Last modified: 18 August 2010
    Name: H5Tis_variable_str
    Signature:
    htri_t H5Tis_variable_str( hid_t dtype_id )

    Purpose:
    Determines whether datatype is a variable-length string.

    Description:
    H5Tis_variable_str determines whether the datatype identified in dtype_id is a variable-length string.

    This function can be used to distinguish between fixed and variable-length string datatypes.

    Parameters:
    hid_t dtype_id     IN: Datatype identifier.

    Returns:
    Returns TRUE or FALSE if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tis_variable_str_f
    SUBROUTINE h5tis_variable_str_f(type_id, status, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id   ! Datatype identifier 
      LOGICAL, INTENT(OUT)       :: status    ! Logical flag:
                                              !    .TRUE. if datatype is a 
                                              !         variable string
                                              !    .FALSE. otherwise 
      INTEGER, INTENT(OUT) :: hdferr          ! Error code
                                              ! 0 on success and -1 on failure
    END SUBROUTINE h5tis_variable_str_f
        

    History:
    Release     C
    1.6.0 Function introduced in this release.

    Last modified: 18 August 2010
    Name: H5Tlock
    Signature:
    herr_t H5Tlock( hid_t dtype_id )

    Purpose:
    Locks a datatype.

    Description:
    H5Tlock locks the datatype specified by the dtype_id identifier, making it read-only and non-destructible. This is normally done by the library for predefined datatypes so the application does not inadvertently change or delete a predefined type. Once a datatype is locked it can never be unlocked.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to lock.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface:
    None.

    Last modified: 29 August 2012
    Name: H5Topen

    Signature:
    hid_t H5Topen( hid_t loc_id, const char * name )

    hid_t H5Topen( hid_t loc_id, const char * name, hid_t tapl_id )

    Purpose:
    Opens a named datatype.

    Description:
    H5Topen is a macro that is mapped to either H5Topen1 or H5Topen2, depending on the needs of the application.

    Such macros are provided to facilitate application compatibility. Their use and mappings are fully described in “API Compatibility Macros in HDF5”; we urge you to read that document closely.

    When both the HDF5 Library and the application are built and installed with no specific compatibility flags, H5Topen is mapped to the most recent version of the function, currently H5Topen2. If the library and/or application is compiled for Release 1.6 emulation, H5Topen will be mapped to H5Topen1. Function-specific flags are available to override these settings on a function-by-function basis when the application is compiled.

    Specific compile-time compatibility flags and the resulting mappings are as follows:

    Compatibility setting H5Topen mapping

    Global settings
    No compatibility flag H5Topen2 
    Enable deprecated symbols H5Topen2 
    Disable deprecated symbols H5Topen2 
    Emulate Release 1.6 interface     H5Topen1 

    Function-level macros
    H5Topen_vers = 2 H5Topen2
    H5Topen_vers = 1 H5Topen1

    The datatype identifier returned by this macro can be released with H5Tclose when the identifier is no longer needed so that resource leaks will not develop.

    Fortran90 Interface: h5topen_f
    SUBROUTINE h5topen_f(loc_id, name, type_id, hdferr, tapl_id)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: loc_id   ! File or group identifier 
      CHARACTER(LEN=*), INTENT(IN) :: name   ! Datatype name within file or group
      INTEGER(HID_T), INTENT(OUT) :: type_id ! Datatype identifier
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
      INTEGER(HID_T), OPTIONAL, INTENT(IN) :: tapl_id 
                                             ! Datatype access property list id
    END SUBROUTINE h5topen_f
        

    History:
    Release     C
    1.8.0 The function H5Topen renamed to H5Topen1 and deprecated in this release.
    The macro H5Topen and the function H5Topen2 introduced in this release.

    Name: H5Topen1
    Signature:
    hid_t H5Topen1( hid_t loc_id, const char * name )

    Purpose:
    Opens a named datatype.

    Notice:
    This function is deprecated in favor of the function H5Topen2.

    Description:
    H5Topen1 opens a named datatype at the location specified by loc_id and returns an identifier for the datatype. loc_id is either a file or group identifier. The identifier should eventually be closed by calling H5Tclose to release resources.

    Parameters:

    Returns:
    Returns a named datatype identifier if successful; otherwise returns a negative value.

    Fortran90 Interface: See listing under H5Topen.

    History:
    Release     C
    1.8.0 The function H5Topen renamed to H5Topen1 and deprecated in this release.

    Name: H5Topen2
    Signature:
    hid_t H5Topen2( hid_t loc_id, const char * name, hid_t tapl_id )

    Purpose:
    Opens a named datatype.

    Description:
    H5Topen2 opens a named datatype at the location specified by loc_id and returns an identifier for the datatype. loc_id is either a file or group identifier. The identifier should eventually be closed by calling H5Tclose to release resources.

    The named datatype is opened with the datatype access property list tapl_id.

    Parameters:

    Returns:
    Returns a named datatype identifier if successful; otherwise returns a negative value.

    Fortran90 Interface: See listing under H5Topen.

    History:

    Last modified: 18 August 2010
    Name: H5Tpack
    Signature:
    herr_t H5Tpack( hid_t dtype_id )

    Purpose:
    Recursively removes padding from within a compound datatype.

    Description:
    H5Tpack recursively removes padding from within a compound datatype to make it more efficient (space-wise) to store that data.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to modify.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tpack_f
    SUBROUTINE h5tpack_f(type_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tpack_f
        

    Last modified: 30 August 2013
    Name: H5Tregister
    Signature:
    herr_t H5Tregister( H5T_pers_t type, const char * name, hid_t src_id, hid_t dst_id, H5T_conv_t func )

    Purpose:
    Registers a conversion function.

    Description:
    H5Tregister registers a hard or soft conversion function for a datatype conversion path.

    The parameter type indicates whether a conversion function is hard (H5T_PERS_HARD) or soft (H5T_PERS_SOFT). User-defined functions employing compiler casting are designated as hard; other user-defined conversion functions registered with the HDF5 Library (with H5Tregister) are designated as soft. The HDF5 Library also has its own hard and soft conversion functions.

    A conversion path can have only one hard function. When type is H5T_PERS_HARD, func replaces any previous hard function.

    When type is H5T_PERS_SOFT, H5Tregister adds the function to the end of the master soft list and replaces the soft function in all applicable existing conversion paths. Soft functions are used when determining which conversion function is appropriate for this path.

    The name is used only for debugging and should be a short identifier for the function.

    The path is specified by the source and destination datatypes src_id and dst_id. For soft conversion functions, only the class of these types is important.

    The type of the conversion function pointer is declared as:

    typedef herr_t (*H5T_conv_t) (hid_t src_id, 
                                  hid_t dst_id, 
                                  H5T_cdata_t *cdata,
                                  size_t nelmts, 
                                  size_t buf_stride, 
                                  size_t bkg_stride, 
                                  void *buf, 
                                  void *bkg,
                                  hid_t dset_xfer_plist)

    The H5T_cdata_t struct is declared as:

    typedef struct *H5T_cdata_t (H5T_cmd_t command, 
                                 H5T_bkg_t need_bkg, 
                                 hbool_t *recalc,
                                 void *priv)

    The H5T_conv_t parameters and the elements of the H5T_cdata_t struct are described more fully in this “Data Conversion” discussion.

    Programming Note for C++ Developers Using C Functions:

    If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.

    Examples of this kind of routine include callbacks such as H5Pset_elink_cb and H5Pset_type_conv_cb and functions such as H5Tconvert and H5Ewalk2.

    Exiting the routine in its normal fashion allows the HDF5 C Library to clean up its work properly. In other words, if the C++ application jumps out of the routine back to the C++ “catch” statement, the library is not given the opportunity to close any temporary data structures that were set up when the routine was called. The C++ application should save some state as the routine is started so that any problem that occurs might be diagnosed.

    Parameters:
    H5T_pers_t type IN: Conversion function type:
      H5T_PERS_HARD for hard conversion functions
      H5T_PERS_SOFT for soft conversion functions
    const char * name IN: Name displayed in diagnostic output
    hid_t src_id IN: Identifier of source datatype
    hid_t dst_id IN: Identifier of destination datatype
    H5T_conv_t func     IN: Function to convert between source and destination datatypes

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface:
    None.

    History:
    Release     C
    1.6.3 The following change occurred in the H5Tconv_t function:
       nelmts parameter type changed to size_t.

    Last modified: 24 June 2013
    Name: H5Tset_cset
    Signature:
    herr_t H5Tset_cset( hid_t dtype_id, H5T_cset_t cset )

    Purpose:
    Sets character set to be used in a string or character datatype.

    Description:
    H5Tset_cset sets the character set to be used in a dataset with a string or character datatype.

    Valid values for cset include the following:
             H5T_CSET_ASCII      Character set is US ASCII.
      H5T_CSET_UTF8   Character set is UTF-8, enabling UTF-8 Unicode encoding.

    For example, if the character set for the datatype dtype_id is set to H5T_CSET_UTF8, string or character data of datatype dtype_id will be encoded using the UTF-8 Unicode character set.

    Note that H5Tset_cset sets the character set for a character or string datatype while H5Pset_char_encoding sets the character set used for an HDF5 link or attribute name.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to modify.
    H5T_cset_t cset     IN: Character set type.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_cset_f
    SUBROUTINE h5tset_cset_f(type_id, cset, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id 
                                      ! Datatype identifier 
      INTEGER, INTENT(IN) :: cset     ! Character set type of a string datatype  
                                      ! Possible values are:
                                      !    H5T_CSET_ASCII_F = 0
                                      !    H5T_CSET_UTF8_F = 1
      INTEGER, INTENT(OUT) :: hdferr  ! Error code
    END SUBROUTINE h5tset_cset_f
        

    History:
    Release     Change
    1.8.0 UTF-8 Unicode encoding introduced in this release.

    Last modified: 19 August 2010
    Name: H5Tset_ebias
    Signature:
    herr_t H5Tset_ebias( hid_t dtype_id, size_t ebias )

    Purpose:
    Sets the exponent bias of a floating-point type.

    Description:
    H5Tset_ebias sets the exponent bias of a floating-point type.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to set.
    size_t ebias IN: Exponent bias value.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_ebias_f
    SUBROUTINE h5tset_ebias_f(type_id, ebias, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(IN) :: ebias  ! Datatype exponent bias 
                                            ! of a floating-point type, 
                                            ! which cannot be 0
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tset_ebias_f
        

    Last modified: 19 August 2010
    Name: H5Tset_fields
    Signature:
    herr_t H5Tset_fields( hid_t dtype_id, size_t spos, size_t epos, size_t esize, size_t mpos, size_t msize )

    Purpose:
    Sets locations and sizes of floating point bit fields.

    Description:
    H5Tset_fields sets the locations and sizes of the various floating-point bit fields. The field positions are bit positions in the significant region of the datatype. Bits are numbered with the least significant bit number zero.

    Fields are not allowed to extend beyond the number of bits of precision, nor are they allowed to overlap with one another.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to set.
    size_t spos IN: Sign position, i.e., the bit offset of the floating-point sign bit.
    size_t epos IN: Exponent bit position.
    size_t esize IN: Size of exponent in bits.
    size_t mpos IN: Mantissa bit position.
    size_t msize IN: Size of mantissa in bits.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_fields_f
    SUBROUTINE h5tset_fields_f(type_id, spos, epos, esize, mpos, msize, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier
      INTEGER(SIZE_T), INTENT(IN) :: spos   ! sign bit-position 
      INTEGER(SIZE_T), INTENT(IN) :: epos   ! exponent bit-position 
      INTEGER(SIZE_T), INTENT(IN) :: esize  ! size of exponent in bits
      INTEGER(SIZE_T), INTENT(IN) :: mpos   ! mantissa bit-position 
      INTEGER(SIZE_T), INTENT(IN) :: msize  ! size of mantissa in bits
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tset_fields_f
        

    Name: H5Tset_inpad
    Signature:
    herr_t H5Tset_inpad( hid_t dtype_id, H5T_pad_t inpad )
    Purpose:
    Fills unused internal floating point bits.
    Description:
    If any internal bits of a floating point type are unused (that is, those significant bits which are not part of the sign, exponent, or mantissa), then H5Tset_inpad will be filled according to the value of the padding value property inpad. Valid padding types are:
    Parameters:
    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tset_inpad_f
    SUBROUTINE h5tset_inpad_f(type_id, padtype, hdferr)
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id 
                                      ! Datatype identifier 
      INTEGER, INTENT(IN) :: padtype  ! Padding type for unused bits 
                                      ! in floating-point datatypes.
                                      ! Possible values of padding type are:
                                      !    H5T_PAD_ZERO_F = 0
                                      !    H5T_PAD_ONE_F = 1
                                      !    H5T_PAD_BACKGROUND_F = 2
      INTEGER, INTENT(OUT) :: hdferr  ! Error code
    END SUBROUTINE h5tset_inpad_f
    	

    Last modified: 19 August 2010
    Name: H5Tset_norm
    Signature:
    herr_t H5Tset_norm( hid_t dtype_id, H5T_norm_t norm )

    Purpose:
    Sets the mantissa normalization of a floating-point datatype.

    Description:
    H5Tset_norm sets the mantissa normalization of a floating-point datatype. Valid normalization types are:

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to set.
    H5T_norm_t norm     IN: Mantissa normalization type.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_norm_f
    SUBROUTINE h5tset_norm_f(type_id, norm, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  
                                      ! Datatype identifier 
      INTEGER, INTENT(IN) :: norm     ! Mantissa normalization of a 
                                      ! floating-point datatype
                                      ! Valid normalization types are:
                                      !    H5T_NORM_IMPLIED_F(0)
                                      !       MSB of mantissa is not stored,
                                      !       always 1 
                                      !    H5T_NORM_MSBSET_F(1) 
                                      !       MSB of mantissa is always 1 
                                      !    H5T_NORM_NONE_F(2)
                                      !       Mantissa is not normalized
      INTEGER, INTENT(OUT) :: hdferr  ! Error code
    END SUBROUTINE h5tset_norm_f
        

    Last modified: 19 August 2010
    Name: H5Tset_offset
    Signature:
    herr_t H5Tset_offset( hid_t dtype_id, size_t offset )

    Purpose:
    Sets the bit offset of the first significant bit.

    Description:
    H5Tset_offset sets the bit offset of the first significant bit. The significant bits of an atomic datum can be offset from the beginning of the memory for that datum by an amount of padding. The offset property specifies the number of bits of padding that appear “to the right of” the value. That is, if we have a 32-bit datum with 16-bits of precision having the value 0x1122, then it will be laid out in memory as (from small byte address toward larger byte addresses):

    Byte Position Big-Endian Offset=0 Big-Endian Offset=16 Little-Endian Offset=0 Little-Endian Offset=16
    0 [ pad] [0x11] [0x22] [ pad]
    1 [ pad] [0x22] [0x11] [ pad]
    2 [0x11] [ pad] [ pad] [0x22]
    3 [0x22] [ pad] [ pad] [0x11]

    If the offset is incremented then the total size is incremented also if necessary to prevent significant bits of the value from hanging over the edge of the datatype.

    The offset of an H5T_STRING cannot be set to anything but zero.

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype to set.
    size_t offset IN: Offset of first significant bit.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_offset_f
    SUBROUTINE h5tset_offset_f(type_id, offset, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(IN) :: offset ! Datatype bit offset of 
                                            ! the first significant bit
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tset_offset_f
        

    Last modified: 24 September 2010
    Name: H5Tset_order
    Signature:
    herr_t H5Tset_order( hid_t dtype_id, H5T_order_t order )

    Purpose:
    Sets the byte order of a datatype.

    Description:
    H5Tset_order sets the byte order of a datatype.

    Byte order can currently be set to any of the following:

    H5T_ORDER_MIXED (3) is a valid value for order only when returned by the function H5Tget_order; it cannot be set with H5Tset_order.

    H5T_ORDER_NONE (4) is a valid value for order, but it has no effect. It is valid only for fixed-length strings and object and region references and specifies “no particular order.”

    The byte order of a derived datatype is initially the same as that of the parent type, but can be changed with H5Tset_order.

    This function cannot be used with a datatype after it has been committed.

    Special considerations:
    ENUM datatypes: Byte order must be set before any member on an ENUM is defined.

    Compound datatypes: Byte order is set individually on each member of a compound datatype; members of a compound datatype need not have the same byte order.

    Opaque datatypes: Byte order can be set but has no effect.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to set.
    H5T_order_t order     IN: Byte order constant.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_order_f
    SUBROUTINE h5tset_order_f(type_id, order, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id   ! Datatype identifier 
      INTEGER, INTENT(IN) :: order            ! Datatype byte order 
                                              ! Possible values are:
                                              !    H5T_ORDER_LE_F 
                                              !    H5T_ORDER_BE_F 
                                              !    H5T_ORDER_VAX_F  
                                              !    H5T_ORDER_NONE_F  
      INTEGER, INTENT(OUT) :: hdferr          ! Error code
                                              ! 0 on success and -1 on failure
    END SUBROUTINE h5tset_order_f
        

    History:
    Release     Change
    1.8.6 Function modified to work with all datatypes.
    H5T_ORDER_MIXED added to H5T_order_t.

    Last modified: 19 August 2010
    Name: H5Tset_pad
    Signature:
    herr_t H5Tset_pad( hid_t dtype_id, H5T_pad_t lsb, H5T_pad_t msb )
    Purpose:
    Sets the least and most-significant bits padding types.

    Description:
    H5Tset_pad sets the least and most-significant bits padding types.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to set.
    H5T_pad_t lsb     IN: Padding type for least-significant bits.
    H5T_pad_t msb IN: Padding type for most-significant bits.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_pad_f
    SUBROUTINE h5tset_pad_f(type_id, lsbpad, msbpad, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      INTEGER, INTENT(IN) :: lsbpad         ! Padding type of the 
                                            ! least significant bit
      INTEGER, INTENT(IN) :: msbpad         ! Padding type of the 
                                            ! most significant bit
                                            ! Possible values of padding 
                                            ! type are:
                                            !    H5T_PAD_ZERO_F = 0
                                            !    H5T_PAD_ONE_F = 1
                                            !    H5T_PAD_BACKGROUND_F = 2
                                            !    H5T_PAD_ERROR_F = -1
                                            !    H5T_PAD_NPAD_F = 3
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tset_pad_f
        

    Last modified: 19 August 2010
    Name: H5Tset_precision
    Signature:
    herr_t H5Tset_precision( hid_t dtype_id, size_tprecision )

    Purpose:
    Sets the precision of an atomic datatype.

    Description:
    H5Tset_precision sets the precision of an atomic datatype. The precision is the number of significant bits which, unless padding is present, is 8 times larger than the value returned by H5Tget_size.

    If the precision is increased then the offset is decreased and then the size is increased to insure that significant bits do not "hang over" the edge of the datatype.

    Changing the precision of an H5T_STRING automatically changes the size as well. The precision must be a multiple of 8.

    When decreasing the precision of a floating point type, set the locations and sizes of the sign, mantissa, and exponent fields first.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to set.
    size_t precision     IN: Number of bits of precision for datatype.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_precision_f
    SUBROUTINE h5tset_precision_f(type_id, precision, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id    ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(IN) :: precision ! Datatype precision
      INTEGER, INTENT(OUT) :: hdferr           ! Error code
    END SUBROUTINE h5tset_precision_f
        

    Last modified: 19 August 2010
    Name: H5Tset_sign
    Signature:
    herr_t H5Tset_sign( hid_t dtype_id, H5T_sign_t sign )

    Purpose:
    Sets the sign property for an integer type.

    Description:
    H5Tset_sign sets the sign property for an integer type:
    H5T_SGN_NONE (0)      Unsigned integer type
    H5T_SGN_2 (1)   Two's complement signed integer type

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to set.
    H5T_sign_t sign     IN: Sign type.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_sign_f
    SUBROUTINE h5tset_sign_f(type_id, sign, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  
                                      ! Datatype identifier 
      INTEGER, INTENT(IN) :: sign     ! Sign type for an integer type 
                                      ! Possible values are:
                                      !    Unsigned integer type 
                                      !       H5T_SGN_NONE_F = 0
                                      !    Two's complement signed integer type
                                      !       H5T_SGN_2_F = 1
                                      !    or error value 
                                      !       H5T_SGN_ERROR_F=-1 
      INTEGER, INTENT(OUT) :: hdferr  ! Error code
    END SUBROUTINE h5tset_sign_f
        

    Last modified: 7 April 2014
    Name: H5Tset_size
    Signature:
    herr_t H5Tset_size( hid_t dtype_id, size_tsize )

    Purpose:
    Sets the total size for a datatype.

    Description:
    H5Tset_size sets the total size in bytes, size, for a datatype.

    The parameter size must have a positive value, unless it is passed as H5T_VARIABLE and the datatype is a string datatype.

    Numeric datatypes: If the datatype is atomic and the size is decreased so that significant bits of the datatype extend beyond the edge of the new size, then the offset property of the datatype is decreased toward zero. If the offset becomes zero and the significant bits of the datatype still hang over the edge of the new size, then the number of significant bits is decreased.

    String or character datatypes: The size set for a string datatype should include space for the null-terminator character, otherwise it will not be stored on (or retrieved from) disk. Adjusting the size of a string automatically sets the precision to 8*size.

    Variable-length string datatypes: If dtype_id is a variable-length string, size must normally be set to H5T_VARIABLE. See “Creating variable-length string datatypes”.

    Compound datatypes: This function may be used to increase or decrease the size of a compound datatype, but the function will fail if the new size is too small to accommodate all member fields.

    Ineligible datatypes: This function cannot be used with enumerated datatypes (H5T_ENUM), array datatypes (H5T_ARRAY), variable-length array datatypes (H5T_VLEN), or reference datatypes (H5T_REFERENCE).

    Parameters:
    hid_t dtype_id     IN: Identifier of datatype for which the size is being changed
    size_t size IN: New datatype size in bytes or H5T_VARIABLE

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    See Also:
    Creating variable-length string datatypes

    Fortran90 Interface: h5tset_size_f
    SUBROUTINE h5tset_size_f(type_id, size, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
      INTEGER(SIZE_T), INTENT(IN) :: size    ! Datatype size
      INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                             ! 0 on success and -1 on failure
    END SUBROUTINE h5tset_size_f
        

    Last modified: 16 April 2013
    Name: H5Tset_strpad
    Signature:
    herr_t H5Tset_strpad( hid_t dtype_id, H5T_str_t strpad )

    Purpose:
    Defines the type of padding used for character strings.

    Description:
    H5Tset_strpad defines the type of padding used for a string datatype.

    The method used to store character strings differs with the programming language:

    Valid values of strpad are as follows:

    H5T_STR_NULLTERM (0)
    Null terminate (as C does).
    H5T_STR_NULLPAD (1)
    Pad with zeros.
    H5T_STR_SPACEPAD (2)
    Pad with spaces (as FORTRAN does).

    When converting from a longer string to a shorter string, the behavior is as follows. If the shorter string is H5T_STR_NULLPAD or H5T_STR_SPACEPAD, then the string is simply truncated. If the short string is H5T_STR_NULLTERM, it is truncated and a null terminator is appended.

    When converting from a shorter string to a longer string, the longer string is padded on the end by appending nulls or spaces.

    Parameters:
    hid_t dtype_id IN: Identifier of datatype to modify.
    H5T_str_t strpad     IN: String padding type.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface: h5tset_strpad_f
    SUBROUTINE h5tset_strpad_f(type_id, strpad, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id 
                                     ! Datatype identifier 
      INTEGER, INTENT(IN) :: strpad  ! String padding method for a string datatype 
                                     ! Possible values of padding type are:
                                     !    Pad with zeros (as C does): 
                                     !       H5T_STR_NULLPAD_F(0)
                                     !    Pad with spaces (as FORTRAN does): 
                                     !       H5T_STR_SPACEPAD_F(1)
      INTEGER, INTENT(OUT) :: hdferr ! Error code
    END SUBROUTINE h5tset_strpad_f
        

    Name: H5Tset_tag
    Signature:
    herr_t H5Tset_tag( hid_t dtype_id const char *tag )
    Purpose:
    Tags an opaque datatype.
    Description:
    H5Tset_tag tags an opaque datatype dtype_id with a descriptive ASCII identifier, tag.

    tag is intended to provide a concise description; the maximum size is hard-coded in the HDF5 Library as 256 bytes (H5T_OPAQUE_TAG_MAX).

    Parameters:
    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.
    Fortran90 Interface: h5tset_tag_f
    SUBROUTINE h5tset_tag_f(type_id, tag, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id ! Datatype identifier 
      CHARACTER(LEN=*), INTENT(IN) :: tag   ! Unique ASCII string with which the
                                            ! opaque datatype is to be tagged 
      INTEGER, INTENT(OUT) :: hdferr        ! Error code
    END SUBROUTINE h5tset_tag_f
    	
    History:

    Last modified: 19 August 2010
    Name: H5Tunregister
    Signature:
    herr_t H5Tunregister( H5T_pers_t type, const char *name, hid_t src_id, hid_t dst_id, H5T_conv_t func )

    Purpose:
    Removes a conversion function.

    Description:
    H5Tunregister removes a conversion function matching criteria such as soft or hard conversion, source and destination types, and the conversion function.

    If a user is trying to remove a conversion function he registered, all parameters can be used. If he is trying to remove a library’s default conversion function, there is no guarantee the name and func parameters will match the user’s chosen values. Passing in some values may cause this function to fail. A good practice is to pass in NULL as their values.

    All parameters are optional. The missing parameters will be used to generalize the search criteria.

    The conversion function pointer type declaration is described in H5Tregister.

    Parameters:
    H5T_pers_t type IN: Conversion function type:
    H5T_PERS_HARD for hard conversion functions or
    H5T_PERS_SOFT for soft conversion functions.
    const char *name IN: Name displayed in diagnostic output.
    hid_t src_id IN: Identifier of source datatype.
    hid_t dst_id IN: Identifier of destination datatype.
    H5T_conv_t func     IN: Function to convert between source and destination datatypes.

    Returns:
    Returns a non-negative value if successful; otherwise returns a negative value.

    Fortran90 Interface:
    None.

    History:
    Release     C
    1.6.3 The following change occurred in the H5Tconv_t function:
       nelmts parameter type changed to size_t.

    Last modified: 24 August 2012
    Name: H5Tvlen_create
    Signature:
    hid_t H5Tvlen_create( hid_t base_type_id )

    Purpose:
    Creates a new variable-length array datatype.

    Description:
    H5Tvlen_create creates a new one-dimensional array datatype of variable-length (VL) with the base datatype base_type_id.

    This one-dimensional array often represents a data sequence of the base datatype, such as characters for character sequences or vertex coordinates for polygon lists. The base type specified for the VL datatype can be any HDF5 datatype, including another VL datatype, a compound datatype, or an atomic datatype.

    When necessary, use H5Tget_super to determine the base type of the VL datatype.

    The datatype identifier returned from this function should be released with H5Tclose or resource leaks will result. Under certain circumstances, H5Dvlen_reclaim must also be used.

    Note:
    H5Tvlen_create cannot be used to create a variable-length string datatype. H5Tvlen_create called with a string or character base type creates a variable-length sequence of strings (a variable-length, 1-dimensional array), with each element of the array being of the string or character base type.

    To create a variable-length string datatype, see “Creating variable-length string datatypes.”

    Parameters:
    hid_t base_type_id     IN: Base type of datatype to create.

    Returns:
    Returns datatype identifier if successful; otherwise returns a negative value.

    See Also:
    H5Dvlen_get_buf_size
    H5Dvlen_reclaim
    Creating variable-length string datatypes

    Fortran90 Interface: h5tvlen_create_f
    SUBROUTINE h5tvlen_create_f(type_id, vltype_id, hdferr) 
      IMPLICIT NONE
      INTEGER(HID_T), INTENT(IN) :: type_id    ! Datatype identifier of base type 
                                               ! Base type can only be atomic 
      INTEGER(HID_T), INTENT(OUT) :: vltype_id ! VL datatype identifier 
      INTEGER, INTENT(OUT) :: hdferr           ! Error code
    END SUBROUTINE h5tvlen_create_f
        

    History:
    Release     Change
    1.4.5 Fortran subroutine introduced in this release.

    HDF5 documents and links 
    Introduction to HDF5 
    HDF5 User Guide 
    In the HDF5 Reference Manual 
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    H5   H5A   H5D   H5E   H5F   H5G   H5I 
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    The HDF Group Help Desk:
    Describes HDF5 Release 1.8.13, May 2014.
      Copyright by The HDF Group
    and the Board of Trustees of the University of Illinois