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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* Copyright by the Board of Trustees of the University of Illinois. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* terms governing use, modification, and redistribution, is contained in *
* the COPYING file, which can be found at the root of the source code *
* distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases. *
* If you do not have access to either file, you may request a copy from *
* help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/************************************************************
This example shows how to read and write data to a
dataset by hyberslabs. The program first writes integers
in a hyperslab selection to a dataset with dataspace
dimensions of DIM_XxDIM_Y, then closes the file. Next, it
reopens the file, reads back the data, and outputs it to
the screen. Finally it reads the data again using a
different hyperslab selection, and outputs the result to
the screen.
************************************************************/
package examples.datasets;
import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
public class H5Ex_D_Hyperslab {
private static String FILENAME = "H5Ex_D_Hyperslab.h5";
private static String DATASETNAME = "DS1";
private static final int DIM_X = 6;
private static final int DIM_Y = 8;
private static final int RANK = 2;
private static void writeHyperslab() {
long file_id = -1;
long filespace_id = -1;
long dataset_id = -1;
long[] dims = { DIM_X, DIM_Y };
int[][] dset_data = new int[DIM_X][DIM_Y];
// Initialize data to "1", to make it easier to see the selections.
for (int indx = 0; indx < DIM_X; indx++)
for (int jndx = 0; jndx < DIM_Y; jndx++)
dset_data[indx][jndx] = 1;
// Print the data to the screen.
System.out.println("Original Data:");
for (int indx = 0; indx < DIM_X; indx++) {
System.out.print(" [ ");
for (int jndx = 0; jndx < DIM_Y; jndx++)
System.out.print(dset_data[indx][jndx] + " ");
System.out.println("]");
}
System.out.println();
// Create a new file using default properties.
try {
file_id = H5.H5Fcreate(FILENAME, HDF5Constants.H5F_ACC_TRUNC, HDF5Constants.H5P_DEFAULT,
HDF5Constants.H5P_DEFAULT);
}
catch (Exception e) {
e.printStackTrace();
}
// Create dataspace. Setting maximum size to NULL sets the maximum
// size to be the current size.
try {
filespace_id = H5.H5Screate_simple(RANK, dims, null);
}
catch (Exception e) {
e.printStackTrace();
}
// Create the dataset. We will use all default properties for this example.
try {
if ((file_id >= 0) && (filespace_id >= 0))
dataset_id = H5.H5Dcreate(file_id, DATASETNAME, HDF5Constants.H5T_STD_I32LE, filespace_id,
HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
}
catch (Exception e) {
e.printStackTrace();
}
// Define and select the first part of the hyperslab selection.
long[] start = { 0, 0 };
long[] stride = { 3, 3 };
long[] count = { 2, 3 };
long[] block = { 2, 2 };
try {
if ((filespace_id >= 0))
H5.H5Sselect_hyperslab(filespace_id, HDF5Constants.H5S_SELECT_SET, start, stride, count, block);
}
catch (Exception e) {
e.printStackTrace();
}
// Define and select the second part of the hyperslab selection,
// which is subtracted from the first selection by the use of
// H5S_SELECT_NOTB
block[0] = 1;
block[1] = 1;
try {
if ((filespace_id >= 0)) {
H5.H5Sselect_hyperslab(filespace_id, HDF5Constants.H5S_SELECT_NOTB, start, stride, count, block);
// Write the data to the dataset.
if (dataset_id >= 0)
H5.H5Dwrite(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, filespace_id,
HDF5Constants.H5P_DEFAULT, dset_data);
}
}
catch (Exception e) {
e.printStackTrace();
}
// End access to the dataset and release resources used by it.
try {
if (dataset_id >= 0)
H5.H5Dclose(dataset_id);
}
catch (Exception e) {
e.printStackTrace();
}
try {
if (filespace_id >= 0)
H5.H5Sclose(filespace_id);
}
catch (Exception e) {
e.printStackTrace();
}
// Close the file.
try {
if (file_id >= 0)
H5.H5Fclose(file_id);
}
catch (Exception e) {
e.printStackTrace();
}
}
private static void readHyperslab() {
long file_id = -1;
long filespace_id = -1;
long dataset_id = -1;
long dcpl_id = -1;
int[][] dset_data = new int[DIM_X][DIM_Y];
// Open an existing file.
try {
file_id = H5.H5Fopen(FILENAME, HDF5Constants.H5F_ACC_RDONLY, HDF5Constants.H5P_DEFAULT);
}
catch (Exception e) {
e.printStackTrace();
}
// Open an existing dataset.
try {
if (file_id >= 0)
dataset_id = H5.H5Dopen(file_id, DATASETNAME, HDF5Constants.H5P_DEFAULT);
}
catch (Exception e) {
e.printStackTrace();
}
// Read the data using the default properties.
try {
if (dataset_id >= 0)
H5.H5Dread(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
HDF5Constants.H5P_DEFAULT, dset_data);
}
catch (Exception e) {
e.printStackTrace();
}
// Output the data to the screen.
System.out.println("Data as written to disk by hyberslabs:");
for (int indx = 0; indx < DIM_X; indx++) {
System.out.print(" [ ");
for (int jndx = 0; jndx < DIM_Y; jndx++)
System.out.print(dset_data[indx][jndx] + " ");
System.out.println("]");
}
System.out.println();
// Initialize the read array.
for (int indx = 0; indx < DIM_X; indx++)
for (int jndx = 0; jndx < DIM_Y; jndx++)
dset_data[indx][jndx] = 0;
// Define and select the hyperslab to use for reading.
try {
if (dataset_id >= 0) {
filespace_id = H5.H5Dget_space(dataset_id);
long[] start = { 0, 1 };
long[] stride = { 4, 4 };
long[] count = { 2, 2 };
long[] block = { 2, 3 };
if (filespace_id >= 0) {
H5.H5Sselect_hyperslab(filespace_id, HDF5Constants.H5S_SELECT_SET, start, stride, count, block);
// Read the data using the previously defined hyperslab.
if ((dataset_id >= 0) && (filespace_id >= 0))
H5.H5Dread(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, filespace_id,
HDF5Constants.H5P_DEFAULT, dset_data);
}
}
}
catch (Exception e) {
e.printStackTrace();
}
// Output the data to the screen.
System.out.println("Data as read from disk by hyberslab:");
for (int indx = 0; indx < DIM_X; indx++) {
System.out.print(" [ ");
for (int jndx = 0; jndx < DIM_Y; jndx++)
System.out.print(dset_data[indx][jndx] + " ");
System.out.println("]");
}
System.out.println();
// End access to the dataset and release resources used by it.
try {
if (dcpl_id >= 0)
H5.H5Pclose(dcpl_id);
}
catch (Exception e) {
e.printStackTrace();
}
try {
if (dataset_id >= 0)
H5.H5Dclose(dataset_id);
}
catch (Exception e) {
e.printStackTrace();
}
try {
if (filespace_id >= 0)
H5.H5Sclose(filespace_id);
}
catch (Exception e) {
e.printStackTrace();
}
// Close the file.
try {
if (file_id >= 0)
H5.H5Fclose(file_id);
}
catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
H5Ex_D_Hyperslab.writeHyperslab();
H5Ex_D_Hyperslab.readHyperslab();
}
}
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