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Diffstat (limited to 'HDF5Examples/JAVA/H5J/HDF5SubsetSelect.java')
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diff --git a/HDF5Examples/JAVA/H5J/HDF5SubsetSelect.java b/HDF5Examples/JAVA/H5J/HDF5SubsetSelect.java new file mode 100644 index 0000000..a00f5be --- /dev/null +++ b/HDF5Examples/JAVA/H5J/HDF5SubsetSelect.java @@ -0,0 +1,264 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * 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 files COPYING and Copyright.html. COPYING can be found at the root * + * of the source code distribution tree; Copyright.html can be found at the * + * root level of an installed copy of the electronic HDF5 document set and * + * is linked from the top-level documents page. It can also be found at * + * http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have * + * access to either file, you may request a copy from help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +import hdf.hdf5lib.H5; +import hdf.hdf5lib.HDF5Constants; + +/** + * <p> + * Title: HDF Native Package (Java) Example + * </p> + * <p> + * Description: this example shows how to select a subset using the + * "HDF Native Package (Java)". The example creates an integer dataset, and read + * subset of the dataset: + * + * <pre> + * "/" (root) + * 2D 32-bit integer 20x10 + * </pre> + * + * The whole 20x10 data set is + * + * <pre> + * 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009 + * 1100, 1101, 1102, 1103, 1104, 1105, 1106, 1107, 1108, 1109 + * 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1209 + * 1300, 1301, 1302, 1303, 1304, 1305, 1306, 1307, 1308, 1309 + * 1400, 1401, 1402, 1403, 1404, 1405, 1406, 1407, 1408, 1409 + * 1500, 1501, 1502, 1503, 1504, 1505, 1506, 1507, 1508, 1509 + * 1600, 1601, 1602, 1603, 1604, 1605, 1606, 1607, 1608, 1609 + * 1700, 1701, 1702, 1703, 1704, 1705, 1706, 1707, 1708, 1709 + * 1800, 1801, 1802, 1803, 1804, 1805, 1806, 1807, 1808, 1809 + * 1900, 1901, 1902, 1903, 1904, 1905, 1906, 1907, 1908, 1909 + * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + * 2100, 2101, 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2109 + * 2200, 2201, 2202, 2203, 2204, 2205, 2206, 2207, 2208, 2209 + * 2300, 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309 + * 2400, 2401, 2402, 2403, 2404, 2405, 2406, 2407, 2408, 2409 + * 2500, 2501, 2502, 2503, 2504, 2505, 2506, 2507, 2508, 2509 + * 2600, 2601, 2602, 2603, 2604, 2605, 2606, 2607, 2608, 2609 + * 2700, 2701, 2702, 2703, 2704, 2705, 2706, 2707, 2708, 2709 + * 2800, 2801, 2802, 2803, 2804, 2805, 2806, 2807, 2808, 2809 + * 2900, 2901, 2902, 2903, 2904, 2905, 2906, 2907, 2908, 2909 + * </pre> + * + * Subset: start=(4, 2), size=(5, 3) and stride=(3, 2). The subset values are: + * + * <pre> + * 1402,1404,1406 + * 1702,1704,1706 + * 2002,2004,2006 + * 2302,2304,2306 + * 2602,2604,2606 + * </pre> + * + * </p> + * + * @author Peter X. Cao + * @version 2.4 + */ +public class HDF5SubsetSelect { + private static String fname = "HDF5SubsetSelect.h5"; + private static String dsname = "2D 32-bit integer 20x10"; + private static long[] dims2D = {20, 10}; + + private static void SubsetSelect() + { + long file_id = HDF5Constants.H5I_INVALID_HID; + long dataset_id = HDF5Constants.H5I_INVALID_HID; + long filespace_id = HDF5Constants.H5I_INVALID_HID; + long memspace_id = HDF5Constants.H5I_INVALID_HID; + + // create the file and add groups and dataset into the file + try { + createFile(); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Open file using the default properties. + try { + file_id = H5.H5Fopen(fname, HDF5Constants.H5F_ACC_RDWR, HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Open dataset using the default properties. + try { + if (file_id >= 0) + dataset_id = H5.H5Dopen(file_id, dsname, HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Allocate array of pointers to two-dimensional arrays (the + // elements of the dataset. + int[][] dataRead = new int[5][3]; + + // Define and select the hyperslab to use for reading. + try { + if (dataset_id >= 0) { + filespace_id = H5.H5Dget_space(dataset_id); + + long[] start = {4, 2}; + long[] stride = {3, 2}; + long[] count = {5, 3}; + long[] block = null; + + if (filespace_id >= 0) { + H5.H5Sselect_hyperslab(filespace_id, HDF5Constants.H5S_SELECT_SET, start, stride, count, + block); + + memspace_id = H5.H5Screate_simple(2, count, null); + // Read the data using the previously defined hyperslab. + if ((dataset_id >= 0) && (filespace_id >= 0) && (memspace_id >= 0)) + H5.H5Dread(dataset_id, HDF5Constants.H5T_NATIVE_INT, memspace_id, filespace_id, + HDF5Constants.H5P_DEFAULT, dataRead); + } + } + } + catch (Exception e) { + e.printStackTrace(); + } + + // print out the data values + System.out.println("\n\nSubset Data Values"); + for (int i = 0; i < 5; i++) { + System.out.print("\n" + dataRead[i][0]); + for (int j = 1; j < 3; j++) { + System.out.print("," + dataRead[i][j]); + } + } + + // Close the dataset. + 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(); + } + } + + /** + * create the file and add groups ans dataset into the file, which is the + * same as javaExample.H5DatasetCreate + * + * @see javaExample.HDF5DatasetCreate + * @throws Exception + */ + private static void createFile() throws Exception + { + long file_id = HDF5Constants.H5I_INVALID_HID; + long dataspace_id = HDF5Constants.H5I_INVALID_HID; + long dataset_id = HDF5Constants.H5I_INVALID_HID; + + // Create a new file using default properties. + try { + file_id = H5.H5Fcreate(fname, HDF5Constants.H5F_ACC_TRUNC, HDF5Constants.H5P_DEFAULT, + HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Create the data space for the dataset. + try { + dataspace_id = H5.H5Screate_simple(2, dims2D, null); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Create the dataset. + try { + if ((file_id >= 0) && (dataspace_id >= 0)) + dataset_id = H5.H5Dcreate(file_id, dsname, HDF5Constants.H5T_STD_I32LE, dataspace_id, + HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT, + HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Terminate access to the data space. + try { + if (dataspace_id >= 0) + H5.H5Sclose(dataspace_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + // set the data values + int[] dataIn = new int[20 * 10]; + for (int i = 0; i < 20; i++) { + for (int j = 0; j < 10; j++) { + dataIn[i * 10 + j] = 1000 + i * 100 + j; + } + } + + // Write the data to the dataset. + try { + if (dataset_id >= 0) + H5.H5Dwrite(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, + HDF5Constants.H5S_ALL, HDF5Constants.H5P_DEFAULT, dataIn); + } + 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(); + } + + // Close the file. + try { + if (file_id >= 0) + H5.H5Fclose(file_id); + } + catch (Exception e) { + e.printStackTrace(); + } + } + + public static void main(String[] args) { HDF5SubsetSelect.SubsetSelect(); } +} |