diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/h5_select.c | 131 |
1 files changed, 115 insertions, 16 deletions
diff --git a/examples/h5_select.c b/examples/h5_select.c index fe4850b..8d587d4 100644 --- a/examples/h5_select.c +++ b/examples/h5_select.c @@ -4,7 +4,9 @@ * Program takes 48 elements from the linear buffer and writes them into * the matrix using 3x2 blocks, (4,3) stride and (2,4) count. * Then four elements of the matrix are overwritten with the new values and - * file is closed. Program reopens the file and reads and displays the result. + * file is closed. Program reopens the file and selects the union of two + * hyperslabs in the dataset in the file. Then it reads the selection into the + * memory dataset preserving the shape of the selectin. */ #include <hdf5.h> @@ -27,7 +29,7 @@ dataspace parameters. */ #define MSPACE_RANK 2 #define MSPACE_DIM1 8 -#define MSPACE_DIM2 12 +#define MSPACE_DIM2 9 #define NPOINTS 4 /* Number of points that will be selected and overwritten */ @@ -35,13 +37,17 @@ int main (void) { hid_t file, dataset; /* File and dataset identifiers */ - hid_t mid1, mid2, fid; /* Dataspace identifiers */ + hid_t mid1, mid2, mid, fid; /* Dataspace identifiers */ hsize_t dim1[] = {MSPACE1_DIM}; /* Dimension size of the first dataset (in memory) */ hsize_t dim2[] = {MSPACE2_DIM}; /* Dimension size of the second dataset (in memory */ hsize_t fdim[] = {FSPACE_DIM1, FSPACE_DIM2}; /* Dimension sizes of the dataset (on disk) */ + hsize_t mdim[] = {MSPACE_DIM1, MSPACE_DIM2}; /* Dimension sizes of the + dataset in memory when we + read selection from the + dataset on the disk */ hssize_t start[2]; /* Start of hyperslab */ hsize_t stride[2]; /* Stride of hyperslab */ @@ -50,11 +56,13 @@ int main (void) hssize_t coord[NPOINTS][FSPACE_RANK]; /* Array to store selected points from the file dataspace */ - herr_t ret; - uint i,j; - int matrix[MSPACE_DIM1][MSPACE_DIM2]; - int vector[MSPACE1_DIM]; - int values[] = {53, 59, 61, 67}; /* New values to be written */ + herr_t ret; + uint i,j; + int matrix[FSPACE_DIM1][FSPACE_DIM2]; /* Buffer to write to the dataset */ + int matrix_out[MSPACE_DIM1][MSPACE_DIM2]; /* Buffer to read from the + dataset */ + int vector[MSPACE1_DIM]; + int values[] = {53, 59, 61, 67}; /* New values to be written */ /* * Buffers' initialization. @@ -62,8 +70,8 @@ int main (void) vector[0] = vector[MSPACE1_DIM - 1] = -1; for (i = 1; i < MSPACE1_DIM - 1; i++) vector[i] = i; - for (i = 0; i < MSPACE_DIM1; i++) { - for (j = 0; j < MSPACE_DIM2; j++) + for (i = 0; i < FSPACE_DIM1; i++) { + for (j = 0; j < FSPACE_DIM2; j++) matrix[i][j] = 0; } @@ -188,21 +196,112 @@ int main (void) /* * Open the dataset. */ - dataset = dataset = H5Dopen(file,"Matrix in file"); + dataset = H5Dopen(file,"Matrix in file"); + + /* + * Get dataspace of the open dataset. + */ + fid = H5Dget_space(dataset); + + /* + * Select first hyperslab for the dataset in the file. The following + * elements are selected: + * 10 0 11 12 + * 18 0 19 20 + * 0 59 0 61 + * + */ + start[0] = 1; start[1] = 2; + block[0] = 1; block[1] = 1; + stride[0] = 1; stride[1] = 1; + count[0] = 3; count[1] = 4; + ret = H5Sselect_hyperslab(fid, H5S_SELECT_SET, start, stride, count, block); + + /* + * Add second selected hyperslab to the selection. + * The following elements are selected: + * 19 20 0 21 22 + * 0 61 0 0 0 + * 27 28 0 29 30 + * 35 36 67 37 38 + * 43 44 0 45 46 + * 0 0 0 0 0 + * Note that two hyperslabs overlap. Common elements are: + * 19 20 + * 0 61 + */ + start[0] = 2; start[1] = 4; + block[0] = 1; block[1] = 1; + stride[0] = 1; stride[1] = 1; + count[0] = 6; count[1] = 5; + ret = H5Sselect_hyperslab(fid, H5S_SELECT_OR, start, stride, count, block); + + /* + * Create memory dataspace. + */ + mid = H5Screate_simple(MSPACE_RANK, mdim, NULL); + + /* + * Select two hyperslabs in memory. Hyperslabs has the same + * size and shape as the selected hyperslabs for the file dataspace. + */ + start[0] = 0; start[1] = 0; + block[0] = 1; block[1] = 1; + stride[0] = 1; stride[1] = 1; + count[0] = 3; count[1] = 4; + ret = H5Sselect_hyperslab(mid, H5S_SELECT_SET, start, stride, count, block); + start[0] = 1; start[1] = 2; + block[0] = 1; block[1] = 1; + stride[0] = 1; stride[1] = 1; + count[0] = 6; count[1] = 5; + ret = H5Sselect_hyperslab(mid, H5S_SELECT_OR, start, stride, count, block); + + /* + * Initialize data buffer. + */ + for (i = 0; i < MSPACE_DIM1; i++) { + for (j = 0; j < MSPACE_DIM2; j++) + matrix_out[i][j] = 0; + } /* - * Read data back to the buffer matrix. + * Read data back to the buffer matrix_out. */ - ret = H5Dread(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, - H5P_DEFAULT, matrix); + ret = H5Dread(dataset, H5T_NATIVE_INT, mid, fid, + H5P_DEFAULT, matrix_out); /* - * Display the result. + * Display the result. Memory dataset is: + * + * 10 0 11 12 0 0 0 0 0 + * 18 0 19 20 0 21 22 0 0 + * 0 59 0 61 0 0 0 0 0 + * 0 0 27 28 0 29 30 0 0 + * 0 0 35 36 67 37 38 0 0 + * 0 0 43 44 0 45 46 0 0 + * 0 0 0 0 0 0 0 0 0 + * 0 0 0 0 0 0 0 0 0 */ for (i=0; i < MSPACE_DIM1; i++) { - for(j=0; j < MSPACE_DIM2; j++) printf("%3d ", matrix[i][j]); + for(j=0; j < MSPACE_DIM2; j++) printf("%3d ", matrix_out[i][j]); printf("\n"); } + /* + * Close memory file and memory dataspaces. + */ + ret = H5Sclose(mid); + ret = H5Sclose(fid); + + /* + * Close dataset. + */ + ret = H5Dclose(dataset); + + /* + * Close the file. + */ + ret = H5Fclose(file); + return 0; } |