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Diffstat (limited to 'doc/html/Tutor/examples/h5_extend.c')
| -rw-r--r-- | doc/html/Tutor/examples/h5_extend.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/doc/html/Tutor/examples/h5_extend.c b/doc/html/Tutor/examples/h5_extend.c new file mode 100644 index 0000000..ae26ed6 --- /dev/null +++ b/doc/html/Tutor/examples/h5_extend.c @@ -0,0 +1,141 @@ +/************************************************************** + * + * This example shows how to work with extendible datasets. + * In the current version of the library a dataset MUST be + * chunked in order to be extendible. + * + * This example is derived from the h5_extend_write.c and + * h5_read_chunk.c examples that are in the "Introduction + * to HDF5". + * + *************************************************************/ + +#include "hdf5.h" + +#define FILE "ext.h5" +#define DATASETNAME "ExtendibleArray" +#define RANK 2 + +int +main (void) +{ + hid_t file; /* handles */ + hid_t dataspace, dataset; + hid_t filespace; + hid_t cparms; + hid_t memspace; + + hsize_t dims[2] = { 3, 3}; /* dataset dimensions + at creation time */ + hsize_t dims1[2] = { 3, 3}; /* data1 dimensions */ + hsize_t dims2[2] = { 7, 1}; /* data2 dimensions */ + + hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED}; + hsize_t size[2]; + hssize_t offset[2]; + hsize_t i,j; + herr_t status, status_n; + int data1[3][3] = { {1, 1, 1}, /* data to write */ + {1, 1, 1}, + {1, 1, 1} }; + + int data2[7] = { 2, 2, 2, 2, 2, 2, 2}; + + /* Variables used in reading data back */ + hsize_t chunk_dims[2] ={2, 5}; + hsize_t chunk_dimsr[2]; + hsize_t dimsr[2]; + int data_out[10][3]; + 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 (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* Modify dataset creation properties, i.e. enable chunking */ + cparms = H5Pcreate (H5P_DATASET_CREATE); + status = H5Pset_chunk ( cparms, RANK, chunk_dims); + + /* Create a new dataset within the file using cparms + creation properties. */ + dataset = H5Dcreate (file, DATASETNAME, H5T_NATIVE_INT, dataspace, + cparms); + + /* Extend the dataset. This call assures that dataset is 3 x 3.*/ + size[0] = 3; + size[1] = 3; + status = H5Dextend (dataset, size); + + /* Select a hyperslab */ + filespace = H5Dget_space (dataset); + offset[0] = 0; + offset[1] = 0; + status = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, offset, NULL, + dims1, NULL); + + /* Write the data to the hyperslab */ + status = H5Dwrite (dataset, H5T_NATIVE_INT, dataspace, filespace, + H5P_DEFAULT, data1); + + /* Extend the dataset. Dataset becomes 10 x 3 */ + dims[0] = dims1[0] + dims2[0]; + size[0] = dims[0]; + size[1] = dims[1]; + status = H5Dextend (dataset, size); + + /* Select a hyperslab */ + filespace = H5Dget_space (dataset); + offset[0] = 3; + offset[1] = 0; + status = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, offset, NULL, + dims2, NULL); + + /* Define memory space */ + dataspace = H5Screate_simple (RANK, dims2, NULL); + + /* Write the data to the hyperslab */ + status = H5Dwrite (dataset, H5T_NATIVE_INT, dataspace, filespace, + H5P_DEFAULT, data2); + + /* Close resources */ + status = H5Dclose (dataset); + status = H5Sclose (dataspace); + status = H5Sclose (filespace); + status = H5Fclose (file); + +/**************************************************************** + Read the data back + ***************************************************************/ + + file = H5Fopen (FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dataset = H5Dopen (file, DATASETNAME); + filespace = H5Dget_space (dataset); + rank = H5Sget_simple_extent_ndims (filespace); + status_n = H5Sget_simple_extent_dims (filespace, dimsr, NULL); + + cparms = H5Dget_create_plist (dataset); + if (H5D_CHUNKED == H5Pget_layout (cparms)) + { + rank_chunk = H5Pget_chunk (cparms, 2, chunk_dimsr); + } + + memspace = H5Screate_simple (rank,dimsr,NULL); + status = H5Dread (dataset, H5T_NATIVE_INT, memspace, filespace, + H5P_DEFAULT, data_out); + printf("\n"); + printf("Dataset: \n"); + for (j = 0; j < dimsr[0]; j++) + { + for (i = 0; i < dimsr[1]; i++) + printf("%d ", data_out[j][i]); + printf("\n"); + } + + status = H5Pclose (cparms); + status = H5Dclose (dataset); + status = H5Sclose (filespace); + status = H5Sclose (memspace); + status = H5Fclose (file); +} |