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 * Copyright by The HDF Group.                                               *
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 * and redistribution, is contained in the files COPYING and Copyright.html. *
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 ****************************************************************************/

package javaExample;

import ncsa.hdf.object.*;     // the common object package
import ncsa.hdf.object.h4.*;  // the HDF4 implementation

/**
 * <p>Title: HDF Object Package (Java) Example</p>
 * <p>Description: this example shows how to create HDF4 datasets using the
 * "HDF Object Package (Java)". The example creates the group structure
 * and datasets:
 * <pre>
 *     "/" (root)
 *         integer arrays
 *             2D 32-bit integer 20x10
 *             3D unsigned 8-bit integer 20x10x5
 *         float arrays
 *             2D 64-bit double 20x10
 *             3D 32-bit float  20x10x5
 * </pre>
 * </p>
 *
 * @author Peter X. Cao
 * @version 2.4
 */
public class H4DatasetCreate
{
    private static String fname = "H4DatasetCreate.hdf";
    private static long[] dims2D = {20, 10};
    private static long[] dims3D = {20, 10, 5};

    public static void main( String args[] ) throws Exception
    {
        // retrieve an instance of H4File
        FileFormat fileFormat = FileFormat.getFileFormat(FileFormat.FILE_TYPE_HDF4);

        if (fileFormat == null)
        {
            System.err.println("Cannot find HDF4 FileFormat.");
            return;
        }

        // create a new file with a given file name.
        H4File testFile = (H4File)fileFormat.create(fname);

        if (testFile == null)
        {
            System.err.println("Failed to create file:"+fname);
            return;
        }

        // open the file and retrieve the root group
        testFile.open();
        Group root = (Group)((javax.swing.tree.DefaultMutableTreeNode)testFile.getRootNode()).getUserObject();

        // create groups at the root
        Group g1 = testFile.createGroup("integer arrays", root);
        Group g2 = testFile.createGroup("float arrays", root);

        // create 2D 32-bit (4 bytes) integer dataset of 20 by 10
        Datatype dtype = testFile.createDatatype(
            Datatype.CLASS_INTEGER, 4, Datatype.NATIVE, Datatype.NATIVE);
        Dataset dataset = testFile.createScalarDS
            ("2D 32-bit integer 20x10", g1, dtype, dims2D, null, null, 0, null);

        // create 3D 8-bit (1 byte) unsigned integer dataset of 20 by 10 by 5
        dtype = testFile.createDatatype(
            Datatype.CLASS_INTEGER, 1, Datatype.NATIVE, Datatype.SIGN_NONE);
        dataset = testFile.createScalarDS
            ("3D 8-bit unsigned integer 20x10x5", g1, dtype, dims3D, null, null, 0, null);

        // create 2D 64-bit (8 bytes) double dataset of 20 by 10
        dtype = testFile.createDatatype(
            Datatype.CLASS_FLOAT, 8, Datatype.NATIVE, -1);
        dataset = testFile.createScalarDS
            ("2D 64-bit double 20x10", g2, dtype, dims2D, null, null, 0, null);

        // create 3D 32-bit (4 bytes) float dataset of 20 by 10 by 5
        dtype = testFile.createDatatype(
            Datatype.CLASS_FLOAT, 4, Datatype.NATIVE, -1);
        dataset = testFile.createScalarDS
            ("3D 32-bit float  20x10x5", g2, dtype, dims3D, null, null, 0, null);

        // close file resource
        testFile.close();
    }
}