!
! The following example shows how to create an external file.
!

     PROGRAM DSETEXTERNAL

     USE HDF5 ! This module contains all necessary modules 
        
     IMPLICIT NONE

     CHARACTER(LEN=7), PARAMETER :: filename = 'extf.h5'  ! File name
     CHARACTER(LEN=4), PARAMETER :: dsetname = "dset-external" ! Dataset name

     INTEGER(HID_T) :: file_id       ! File identifier 
     INTEGER(HID_T) :: dset_id       ! Dataset identifier 
     INTEGER(HID_T) :: dspace_id     ! Dataspace identifier
     INTEGER(HID_T) :: dcpl          ! Dataset Creation Property List ID
     INTEGER(HSIZE_T) :: size        ! Size of external dataset

     INTEGER     ::   error ! Error flag
     INTEGER     ::  i, j

     INTEGER, DIMENSION(4,6) :: dset_data
     INTEGER(HSIZE_T), DIMENSION(2) :: data_dims


     INTEGER(HSIZE_T), DIMENSION(2) :: dims = (/4,6/) ! Dataset dimensions
     INTEGER     ::   rank = 2                        ! Dataset rank

     ! Initialize FORTRAN predefined datatypes.
     !
     CALL h5open_f (error)

     ! Create a new file 
     ! 
     CALL h5fcreate_f (filename, H5F_ACC_TRUNC_F, file_id, error, &
                       H5P_DEFAULT_F, H5P_DEFAULT_F)

     ! Create the dataspace.
     !
     CALL h5screate_simple_f (rank, dims, dspace_id, error)

     size = dims(1)* dims(2) * 4 
    
     ! Set Dataset Creation Property List to create external dataset.
     !
     CALL h5pcreate_f(H5P_DATASET_CREATE_F, dcpl, error) 
     CALL h5pset_external_f (dcpl, "extf.dat", 0, size, error)

     ! Create the dataset with default properties.
     !
     CALL h5dcreate_f (file_id, dsetname, H5T_NATIVE_INTEGER, dspace_id, &
                       dset_id, error, dcpl)

     ! Initialize the dset_data array.
     !
     do i = 1, 4
          do j = 1, 6
               dset_data(i,j) = (i-1)*6 + j;
          end do
     end do

     ! Write the dataset.
     !
     data_dims(1) = 4
     data_dims(2) = 6
     CALL h5dwrite_f(dset_id, H5T_NATIVE_INTEGER, dset_data, data_dims, error)

     ! End access to the dataset, dataspace, property list, and file.
     ! 
     CALL h5pclose_f (dcpl, error)
     CALL h5dclose_f (dset_id, error)
     CALL h5sclose_f (dspace_id, error)
     CALL h5fclose_f (file_id, error)

     ! Close FORTRAN predefined datatypes.
     !
     CALL h5close_f (error)

     END PROGRAM DSETEXTERNAL