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Diffstat (limited to 'examples/h5_extend.c')
| -rw-r--r-- | examples/h5_extend.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/examples/h5_extend.c b/examples/h5_extend.c new file mode 100644 index 0000000..128c715 --- /dev/null +++ b/examples/h5_extend.c @@ -0,0 +1,146 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * 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 how to work with extendible datasets. The dataset + * must be chunked in order to be extendible. + * + * It is used in the HDF5 Tutorial. + */ + + +#include "hdf5.h" + +#define FILENAME "extend.h5" +#define DATASETNAME "ExtendibleArray" +#define RANK 2 + +int +main (void) +{ + hid_t file; /* handles */ + hid_t dataspace, dataset; + hid_t filespace, memspace; + hid_t prop; + + hsize_t dims[2] = {3, 3}; /* dataset dimensions at creation time */ + hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED}; + herr_t status; + hsize_t chunk_dims[2] = {2, 5}; + int data[3][3] = { {1, 1, 1}, /* data to write */ + {1, 1, 1}, + {1, 1, 1} }; + + /* Variables used in extending and writing to the extended portion of dataset */ + hsize_t size[2]; + hsize_t offset[2]; + hsize_t dimsext[2] = {7, 3}; /* extend dimensions */ + int dataext[7][3] = { {2, 3, 4}, + {2, 3, 4}, + {2, 3, 4}, + {2, 3, 4}, + {2, 3, 4}, + {2, 3, 4}, + {2, 3, 4} }; + + /* Variables used in reading data back */ + hsize_t chunk_dimsr[2]; + hsize_t dimsr[2]; + hsize_t i, j; + int rdata[10][3]; + herr_t status_n; + int rank, rank_chunk; + + /* Create the data space with unlimited dimensions. */ + dataspace = H5Screate_simple (RANK, dims, maxdims); + + /* Create a new file. If file exists its contents will be overwritten. */ + file = H5Fcreate (FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* Modify dataset creation properties, i.e. enable chunking */ + prop = H5Pcreate (H5P_DATASET_CREATE); + status = H5Pset_chunk (prop, RANK, chunk_dims); + + /* Create a new dataset within the file using chunk + creation properties. */ + dataset = H5Dcreate (file, DATASETNAME, H5T_NATIVE_INT, dataspace, + H5P_DEFAULT, prop, H5P_DEFAULT); + + /* Write data to dataset */ + status = H5Dwrite (dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, + H5P_DEFAULT, data); + + /* Extend the dataset. Dataset becomes 10 x 3 */ + size[0] = dims[0]+ dimsext[0]; + size[1] = dims[1]; + status = H5Dextend (dataset, size); + + /* Select a hyperslab in extended portion of dataset */ + filespace = H5Dget_space (dataset); + offset[0] = 3; + offset[1] = 0; + status = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, offset, NULL, + dimsext, NULL); + + /* Define memory space */ + memspace = H5Screate_simple (RANK, dimsext, NULL); + + /* Write the data to the extended portion of dataset */ + status = H5Dwrite (dataset, H5T_NATIVE_INT, memspace, filespace, + H5P_DEFAULT, dataext); + + /* Close resources */ + status = H5Dclose (dataset); + status = H5Pclose (prop); + status = H5Sclose (dataspace); + status = H5Sclose (memspace); + status = H5Sclose (filespace); + status = H5Fclose (file); + + /******************************************** + * Re-open the file and read the data back. * + ********************************************/ + + file = H5Fopen (FILENAME, H5F_ACC_RDONLY, H5P_DEFAULT); + dataset = H5Dopen (file, DATASETNAME, H5P_DEFAULT); + + filespace = H5Dget_space (dataset); + rank = H5Sget_simple_extent_ndims (filespace); + status_n = H5Sget_simple_extent_dims (filespace, dimsr, NULL); + + prop = H5Dget_create_plist (dataset); + + if (H5D_CHUNKED == H5Pget_layout (prop)) + rank_chunk = H5Pget_chunk (prop, rank, chunk_dimsr); + + memspace = H5Screate_simple (rank, dimsr, NULL); + status = H5Dread (dataset, H5T_NATIVE_INT, memspace, filespace, + H5P_DEFAULT, rdata); + + printf("\n"); + printf("Dataset: \n"); + for (j = 0; j < dimsr[0]; j++) + { + for (i = 0; i < dimsr[1]; i++) + printf("%d ", rdata[j][i]); + printf("\n"); + } + + status = H5Pclose (prop); + status = H5Dclose (dataset); + status = H5Sclose (filespace); + status = H5Sclose (memspace); + status = H5Fclose (file); +} |