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Diffstat (limited to 'HDF5Examples/C/H5D/h5ex_d_chunk.c')
| -rw-r--r-- | HDF5Examples/C/H5D/h5ex_d_chunk.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5D/h5ex_d_chunk.c b/HDF5Examples/C/H5D/h5ex_d_chunk.c new file mode 100644 index 0000000..df6d235 --- /dev/null +++ b/HDF5Examples/C/H5D/h5ex_d_chunk.c @@ -0,0 +1,219 @@ +/************************************************************ + + This example shows how to create a chunked dataset. The + program first writes integers in a hyperslab selection to + a chunked dataset with dataspace dimensions of DIM0xDIM1 + and chunk size of CHUNK0xCHUNK1, then closes the file. + Next, it reopens the file, reads back the data, and + outputs it to the screen. Finally it reads the data again + using a different hyperslab selection, and outputs + the result to the screen. + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_d_chunk.h5" +#define DATASET "DS1" +#define DIM0 6 +#define DIM1 8 +#define CHUNK0 4 +#define CHUNK1 4 + +int +main(void) +{ + hid_t file = H5I_INVALID_HID; + hid_t space = H5I_INVALID_HID; + hid_t dset = H5I_INVALID_HID; + hid_t dcpl = H5I_INVALID_HID; + herr_t status; + H5D_layout_t layout; + hsize_t dims[2] = {DIM0, DIM1}; + hsize_t chunk[2] = {CHUNK0, CHUNK1}; + hsize_t start[2]; + hsize_t stride[2]; + hsize_t count[2]; + hsize_t block[2]; + int wdata[DIM0][DIM1]; /* Write buffer */ + int rdata[DIM0][DIM1]; /* Read buffer */ + hsize_t i, j; + + /* + * Initialize data to "1", to make it easier to see the selections. + */ + for (i = 0; i < DIM0; i++) + for (j = 0; j < DIM1; j++) + wdata[i][j] = 1; + + /* + * Print the data to the screen. + */ + printf("Original Data:\n"); + for (i = 0; i < DIM0; i++) { + printf(" ["); + for (j = 0; j < DIM1; j++) + printf(" %3d", wdata[i][j]); + printf("]\n"); + } + + /* + * Create a new file using the default properties. + */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* + * Create dataspace. Setting maximum size to NULL sets the maximum + * size to be the current size. + */ + space = H5Screate_simple(2, dims, NULL); + + /* + * Create the dataset creation property list, and set the chunk + * size. + */ + dcpl = H5Pcreate(H5P_DATASET_CREATE); + status = H5Pset_chunk(dcpl, 2, chunk); + + /* + * Create the chunked dataset. + */ + dset = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT); + + /* + * Define and select the first part of the hyperslab selection. + */ + start[0] = 0; + start[1] = 0; + stride[0] = 3; + stride[1] = 3; + count[0] = 2; + count[1] = 3; + block[0] = 2; + block[1] = 2; + status = H5Sselect_hyperslab(space, H5S_SELECT_SET, start, stride, count, block); + + /* + * Define and select the second part of the hyperslab selection, + * which is subtracted from the first selection by the use of + * H5S_SELECT_NOTB + */ + block[0] = 1; + block[1] = 1; + status = H5Sselect_hyperslab(space, H5S_SELECT_NOTB, start, stride, count, block); + + /* + * Write the data to the dataset. + */ + status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, space, H5P_DEFAULT, wdata[0]); + + /* + * Close and release resources. + */ + status = H5Pclose(dcpl); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Fclose(file); + + /* + * Now we begin the read section of this example. + */ + + /* + * Open file and dataset using the default properties. + */ + file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dset = H5Dopen(file, DATASET, H5P_DEFAULT); + + /* + * Retrieve the dataset creation property list, and print the + * storage layout. + */ + dcpl = H5Dget_create_plist(dset); + layout = H5Pget_layout(dcpl); + printf("\nStorage layout for %s is: ", DATASET); + switch (layout) { + case H5D_COMPACT: + printf("H5D_COMPACT\n"); + break; + case H5D_CONTIGUOUS: + printf("H5D_CONTIGUOUS\n"); + break; + case H5D_CHUNKED: + printf("H5D_CHUNKED\n"); + break; +#if H5_VERSION_GE(1, 10, 0) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + case H5D_VIRTUAL: + printf("H5D_VIRTUAL\n"); + break; +#endif + case H5D_LAYOUT_ERROR: + case H5D_NLAYOUTS: + printf("H5D_LAYOUT_ERROR\n"); + } + + /* + * Read the data using the default properties. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata[0]); + + /* + * Output the data to the screen. + */ + printf("\nData as written to disk by hyberslabs:\n"); + for (i = 0; i < DIM0; i++) { + printf(" ["); + for (j = 0; j < DIM1; j++) + printf(" %3d", rdata[i][j]); + printf("]\n"); + } + + /* + * Initialize the read array. + */ + for (i = 0; i < DIM0; i++) + for (j = 0; j < DIM1; j++) + rdata[i][j] = 0; + + /* + * Define and select the hyperslab to use for reading. + */ + space = H5Dget_space(dset); + start[0] = 0; + start[1] = 1; + stride[0] = 4; + stride[1] = 4; + count[0] = 2; + count[1] = 2; + block[0] = 2; + block[1] = 3; + status = H5Sselect_hyperslab(space, H5S_SELECT_SET, start, stride, count, block); + + /* + * Read the data using the previously defined hyperslab. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, space, H5P_DEFAULT, rdata[0]); + + /* + * Output the data to the screen. + */ + printf("\nData as read from disk by hyperslab:\n"); + for (i = 0; i < DIM0; i++) { + printf(" ["); + for (j = 0; j < DIM1; j++) + printf(" %3d", rdata[i][j]); + printf("]\n"); + } + + /* + * Close and release resources. + */ + status = H5Pclose(dcpl); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Fclose(file); + + return 0; +} |