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Diffstat (limited to 'examples/h5_subset.c')
| -rw-r--r-- | examples/h5_subset.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/examples/h5_subset.c b/examples/h5_subset.c new file mode 100644 index 0000000..eec0a2f --- /dev/null +++ b/examples/h5_subset.c @@ -0,0 +1,153 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * 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. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * This example illustrates how to read/write a subset of data (a slab) + * from/to a dataset in an HDF5 file. It is used in the HDF5 Tutorial. + */ + +#include "hdf5.h" + +#define FILE "subset.h5" +#define DATASETNAME "IntArray" +#define RANK 2 + +#define DIM0_SUB 3 /* subset dimensions */ +#define DIM1_SUB 4 + + +#define DIM0 8 /* size of dataset */ +#define DIM1 10 + +int +main (void) +{ + hsize_t dims[2], dimsm[2]; + int data[DIM0][DIM1]; /* data to write */ + int sdata[DIM0_SUB][DIM1_SUB]; /* subset to write */ + int rdata[DIM0][DIM1]; /* buffer for read */ + + hid_t file_id, dataset_id; /* handles */ + hid_t dataspace_id, memspace_id; + + herr_t status; + + hsize_t count[2]; /* size of subset in the file */ + hsize_t offset[2]; /* subset offset in the file */ + hsize_t stride[2]; + hsize_t block[2]; + int i, j; + + + /***************************************************************** + * Create a new file with default creation and access properties.* + * Then create a dataset and write data to it and close the file * + * and dataset. * + *****************************************************************/ + + file_id = H5Fcreate (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + dims[0] = DIM0; + dims[1] = DIM1; + dataspace_id = H5Screate_simple (RANK, dims, NULL); + + dataset_id = H5Dcreate (file_id, DATASETNAME, H5T_STD_I32BE, dataspace_id, + H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + + + for (j = 0; j < DIM0; j++) { + for (i = 0; i < DIM1; i++) + if (i< (DIM1/2)) + data[j][i] = 1; + else + data[j][i] = 2; + } + + status = H5Dwrite (dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, + H5P_DEFAULT, data); + + printf ("\nData Written to File:\n"); + for (i = 0; i<DIM0; i++){ + for (j = 0; j<DIM1; j++) + printf (" %i", data[i][j]); + printf ("\n"); + } + status = H5Sclose (dataspace_id); + status = H5Dclose (dataset_id); + status = H5Fclose (file_id); + + + /***************************************************** + * Reopen the file and dataset and write a subset of * + * values to the dataset. + *****************************************************/ + + file_id = H5Fopen (FILE, H5F_ACC_RDWR, H5P_DEFAULT); + dataset_id = H5Dopen (file_id, DATASETNAME, H5P_DEFAULT); + + /* Specify size and shape of subset to write. */ + + offset[0] = 1; + offset[1] = 2; + + count[0] = DIM0_SUB; + count[1] = DIM1_SUB; + + stride[0] = 1; + stride[1] = 1; + + block[0] = 1; + block[1] = 1; + + /* Create memory space with size of subset. Get file dataspace + and select subset from file dataspace. */ + + dimsm[0] = DIM0_SUB; + dimsm[1] = DIM1_SUB; + memspace_id = H5Screate_simple (RANK, dimsm, NULL); + + dataspace_id = H5Dget_space (dataset_id); + status = H5Sselect_hyperslab (dataspace_id, H5S_SELECT_SET, offset, + stride, count, block); + + /* Write a subset of data to the dataset, then read the + entire dataset back from the file. */ + + printf ("\nWrite subset to file specifying:\n"); + printf (" offset=1x2 stride=1x1 count=3x4 block=1x1\n"); + for (j = 0; j < DIM0_SUB; j++) { + for (i = 0; i < DIM1_SUB; i++) + sdata[j][i] = 5; + } + + status = H5Dwrite (dataset_id, H5T_NATIVE_INT, memspace_id, + dataspace_id, H5P_DEFAULT, sdata); + + status = H5Dread (dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, + H5P_DEFAULT, rdata); + + printf ("\nData in File after Subset is Written:\n"); + for (i = 0; i<DIM0; i++){ + for (j = 0; j<DIM1; j++) + printf (" %i", rdata[i][j]); + printf ("\n"); + } + + status = H5Sclose (memspace_id); + status = H5Sclose (dataspace_id); + status = H5Dclose (dataset_id); + status = H5Fclose (file_id); + +} |