diff options
Diffstat (limited to 'doc/html/Tutor/examples/h5_read.c')
| -rw-r--r-- | doc/html/Tutor/examples/h5_read.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/doc/html/Tutor/examples/h5_read.c b/doc/html/Tutor/examples/h5_read.c new file mode 100644 index 0000000..31cb882 --- /dev/null +++ b/doc/html/Tutor/examples/h5_read.c @@ -0,0 +1,136 @@ +/* + * This example reads hyperslab from the SDS.h5 file + * created by h5_write.c program into two-dimensional + * plane of the three-dimensional array. + * Information about dataset in the SDS.h5 file is obtained. + */ + +#include "hdf5.h" + +#define FILE "SDS.h5" +#define DATASETNAME "IntArray" +#define NX_SUB 3 /* hyperslab dimensions */ +#define NY_SUB 4 +#define NX 7 /* output buffer dimensions */ +#define NY 7 +#define NZ 3 +#define RANK 2 +#define RANK_OUT 3 + +int +main (void) +{ + hid_t file, dataset; /* handles */ + hid_t datatype, dataspace; + hid_t memspace; + H5T_class_t class; /* data type class */ + H5T_order_t order; /* data order */ + size_t size; /* + * size of the data element + * stored in file + */ + hsize_t dimsm[3]; /* memory space dimensions */ + hsize_t dims_out[2]; /* dataset dimensions */ + herr_t status; + + int data_out[NX][NY][NZ ]; /* output buffer */ + + hsize_t count[2]; /* size of the hyperslab in the file */ + hssize_t offset[2]; /* hyperslab offset in the file */ + hsize_t count_out[3]; /* size of the hyperslab in memory */ + hssize_t offset_out[3]; /* hyperslab offset in memory */ + int i, j, k, status_n, rank; + + for (j = 0; j < NX; j++) { + for (i = 0; i < NY; i++) { + for (k = 0; k < NZ ; k++) + data_out[j][i][k] = 0; + } + } + + /* + * Open the file and the dataset. + */ + file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dataset = H5Dopen(file, DATASETNAME); + + /* + * Get datatype and dataspace handles and then query + * dataset class, order, size, rank and dimensions. + */ + datatype = H5Dget_type(dataset); /* datatype handle */ + class = H5Tget_class(datatype); + if (class == H5T_INTEGER) printf("Data set has INTEGER type \n"); + order = H5Tget_order(datatype); + if (order == H5T_ORDER_LE) printf("Little endian order \n"); + + size = H5Tget_size(datatype); + printf(" Data size is %d \n", size); + + dataspace = H5Dget_space(dataset); /* dataspace handle */ + rank = H5Sget_simple_extent_ndims(dataspace); + status_n = H5Sget_simple_extent_dims(dataspace, dims_out, NULL); + printf("rank %d, dimensions %lu x %lu \n", rank, + (unsigned long)(dims_out[0]), (unsigned long)(dims_out[1])); + + /* + * Define hyperslab in the dataset. + */ + offset[0] = 1; + offset[1] = 2; + count[0] = NX_SUB; + count[1] = NY_SUB; + status = H5Sselect_hyperslab(dataspace, H5S_SELECT_SET, offset, NULL, + count, NULL); + + /* + * Define the memory dataspace. + */ + dimsm[0] = NX; + dimsm[1] = NY; + dimsm[2] = NZ ; + memspace = H5Screate_simple(RANK_OUT,dimsm,NULL); + + /* + * Define memory hyperslab. + */ + offset_out[0] = 3; + offset_out[1] = 0; + offset_out[2] = 0; + count_out[0] = NX_SUB; + count_out[1] = NY_SUB; + count_out[2] = 1; + status = H5Sselect_hyperslab(memspace, H5S_SELECT_SET, offset_out, NULL, + count_out, NULL); + + /* + * Read data from hyperslab in the file into the hyperslab in + * memory and display. + */ + status = H5Dread(dataset, H5T_NATIVE_INT, memspace, dataspace, + H5P_DEFAULT, data_out); + for (j = 0; j < NX; j++) { + for (i = 0; i < NY; i++) printf("%d ", data_out[j][i][0]); + printf("\n"); + } + /* + * 0 0 0 0 0 0 0 + * 0 0 0 0 0 0 0 + * 0 0 0 0 0 0 0 + * 3 4 5 6 0 0 0 + * 4 5 6 7 0 0 0 + * 5 6 7 8 0 0 0 + * 0 0 0 0 0 0 0 + */ + + /* + * Close/release resources. + */ + H5Tclose(datatype); + H5Dclose(dataset); + H5Sclose(dataspace); + H5Sclose(memspace); + H5Fclose(file); + + return 0; +} |