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author | Elena Pourmal <epourmal@hdfgroup.org> | 1998-08-31 21:36:28 (GMT) |
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committer | Elena Pourmal <epourmal@hdfgroup.org> | 1998-08-31 21:36:28 (GMT) |
commit | 65dea75ab8146583a30bd2b84e4b2202a2afe438 (patch) | |
tree | d9ac01ff31e5c89eb907e9e59b19ff9f9c2cb42e /examples/h5_select.c | |
parent | 0d7ec99e1dbcaafa8c39495df555acd7b7ad63bb (diff) | |
download | hdf5-65dea75ab8146583a30bd2b84e4b2202a2afe438.zip hdf5-65dea75ab8146583a30bd2b84e4b2202a2afe438.tar.gz hdf5-65dea75ab8146583a30bd2b84e4b2202a2afe438.tar.bz2 |
[svn-r639] Two new examples h5_select.c and h5_attribute.c were added to the directory.
Makefile.in was modified to reflect those changes.
Tested on Sun Sparc ( baldric) and DEC Alpha (gondolin)
Diffstat (limited to 'examples/h5_select.c')
-rw-r--r-- | examples/h5_select.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/examples/h5_select.c b/examples/h5_select.c new file mode 100644 index 0000000..4de93e0 --- /dev/null +++ b/examples/h5_select.c @@ -0,0 +1,204 @@ +/* + * This program shows how the H5Sselect_hyperslab and H5Sselect_elements + * functions are used to write selected data from memory to the file. + * 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. + */ + +#include <hdf5.h> + +#define FILE "Select.h5" + +#define MSPACE1_RANK 1 /* Rank of the first dataset in memory */ +#define MSPACE1_DIM 50 /* Dataset size in memory */ + +#define MSPACE2_RANK 1 /* Rank of the second dataset in memory */ +#define MSPACE2_DIM 4 /* Dataset size in memory */ + +#define FSPACE_RANK 2 /* Dataset rank as it is stored in the file */ +#define FSPACE_DIM1 8 /* Dimension sizes of the dataset as it is + stored in the file */ +#define FSPACE_DIM2 12 + + /* We will read dataset back from the file + to the dataset in memory with these + dataspace parameters. */ +#define MSPACE_RANK 2 +#define MSPACE_DIM1 8 +#define MSPACE_DIM2 12 + +#define NPOINTS 4 /* Number of points that will be selected + and overwritten */ +int main (void) +{ + + hid_t file, dataset; /* File and dataset identifiers */ + hid_t mid1, mid2, 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) */ + + hssize_t start[2]; /* Start of hyperslab */ + hsize_t stride[2]; /* Stride of hyperslab */ + hsize_t count[2]; /* Block count */ + hsize_t block[2]; /* Block sizes */ + + 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 */ +/* + * Buffers' initialization. + */ +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++) + matrix[i][j] = 0; +} +/* + * Create a file. + */ +file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + +/* + * Create dataspace for the dataset in the file. + */ +fid = H5Screate_simple(FSPACE_RANK, fdim, NULL); + +/* + * Create dataset and write it into the file. + */ +dataset = H5Dcreate(file, "Matrix in file", H5T_NATIVE_INT, fid, H5P_DEFAULT); +ret = H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, matrix); + +/* + * Select hyperslab for the dataset in the file, using 3x2 blocks, (4,3) stride + * (2,4) count starting at the position (0,1). + */ +start[0] = 0; start[1] = 1; +stride[0] = 4; stride[1] = 3; +count[0] = 2; count[1] = 4; +block[0] = 3; block[1] = 2; +ret = H5Sselect_hyperslab(fid, H5S_SELECT_SET, start, stride, count, block); + +/* + * Create dataspace for the first dataset. + */ +mid1 = H5Screate_simple(MSPACE1_RANK, dim1, NULL); + +/* + * Select hyperslab. + * We will use 48 elements of the vector buffer starting at the second element. + * Selected elements are 1 2 3 . . . 48 + */ +start[0] = 1; +stride[0] = 1; +count[0] = 48; +block[0] = 1; +ret = H5Sselect_hyperslab(mid1, H5S_SELECT_SET, start, stride, count, block); + +/* + * Write selection from the vector buffer to the dataset in the file. + * + * File dataset should look like this: + * 0 1 2 0 3 4 0 5 6 0 7 8 + * 0 9 10 0 11 12 0 13 14 0 15 16 + * 0 17 18 0 19 20 0 21 22 0 23 24 + * 0 0 0 0 0 0 0 0 0 0 0 0 + * 0 25 26 0 27 28 0 29 30 0 31 32 + * 0 33 34 0 35 36 0 37 38 0 39 40 + * 0 41 42 0 43 44 0 45 46 0 47 48 + * 0 0 0 0 0 0 0 0 0 0 0 0 + */ +ret = H5Dwrite(dataset, H5T_NATIVE_INT, mid1, fid, H5P_DEFAULT, vector); + +/* + * Reset the selection for the file dataspace fid. + */ +ret = H5Sselect_none(fid); + +/* + * Create dataspace for the second dataset. + */ +mid2 = H5Screate_simple(MSPACE2_RANK, dim2, NULL); + +/* + * Select sequence of NPOINTS points in the file dataspace. + */ +coord[0][0] = 0; coord[0][1] = 0; +coord[1][0] = 3; coord[1][1] = 3; +coord[2][0] = 3; coord[2][1] = 5; +coord[3][0] = 5; coord[3][1] = 6; + +ret = H5Sselect_elements(fid, H5S_SELECT_SET, NPOINTS, + (const hssize_t **)coord); + +/* + * Write new selection of points to the dataset. + */ +ret = H5Dwrite(dataset, H5T_NATIVE_INT, mid2, fid, H5P_DEFAULT, values); + +/* + * File dataset should look like this: + * 53 1 2 0 3 4 0 5 6 0 7 8 + * 0 9 10 0 11 12 0 13 14 0 15 16 + * 0 17 18 0 19 20 0 21 22 0 23 24 + * 0 0 0 59 0 61 0 0 0 0 0 0 + * 0 25 26 0 27 28 0 29 30 0 31 32 + * 0 33 34 0 35 36 67 37 38 0 39 40 + * 0 41 42 0 43 44 0 45 46 0 47 48 + * 0 0 0 0 0 0 0 0 0 0 0 0 + * + */ + +/* + * Close memory file and memory dataspaces. + */ +ret = H5Sclose(mid1); +ret = H5Sclose(mid2); +ret = H5Sclose(fid); + +/* + * Close dataset. + */ +ret = H5Dclose(dataset); + +/* + * Close the file. + */ +ret = H5Fclose(file); +/* + * Open the file. + */ +file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + +/* + * Open the dataset. + */ +dataset = dataset = H5Dopen(file,"Matrix in file"); + +/* + * Read data back to the buffer matrix. + */ +ret = H5Dread(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, + H5P_DEFAULT, matrix); + +/* + * Display the result. + */ +for (i=0; i < MSPACE_DIM1; i++) { + for(j=0; j < MSPACE_DIM2; j++) printf("%3d ", matrix[i][j]); + printf("\n"); +} +return 0; +} |