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Diffstat (limited to 'examples/h5_read.c')
| -rw-r--r-- | examples/h5_read.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/examples/h5_read.c b/examples/h5_read.c new file mode 100644 index 0000000..99e1801 --- /dev/null +++ b/examples/h5_read.c @@ -0,0 +1,128 @@ +/* + * This example reads hyperslab from the SDS.h5 file + * created by h5_write.c program into two-dimensional + * plane of the tree-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 + +main () +{ + 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 */ + size_t dimsm[3]; /* memory space dimensions */ + size_t dims_out[2]; /* dataset dimensions */ + herr_t status; + + int data_out[NX][NY][NZ ]; /* output buffer */ + + size_t count[2]; /* size of the hyperslab in the file */ + int offset[2]; /* hyperslab offset in the file */ + size_t count_out[3]; /* size of the hyperslab in memory */ + int 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, H5ACC_DEFAULT, H5C_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 = H5Pget_ndims(dataspace); +status_n = H5Pget_dims(dataspace, dims_out); +printf("rank %d, dimensions %d x %d \n", rank, dims_out[0], dims_out[1]); + +/* + * Define hyperslab in the datatset. + */ +offset[0] = 1; +offset[1] = 2; +count[0] = NX_SUB; +count[1] = NY_SUB; +status = H5Pset_hyperslab(dataspace, offset, count, NULL); + +/* + * Define the memory dataspace. + */ +dimsm[0] = NX; +dimsm[1] = NY; +dimsm[2] = NZ ; +memspace = H5Pcreate_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 = H5Pset_hyperslab(memspace, offset_out, 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, + H5C_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); +H5Pclose(dataspace); +H5Pclose(memspace); +H5Fclose(file); + +} |