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Diffstat (limited to 'HDF5Examples/C/H5D/h5ex_d_fillval.c')
-rw-r--r-- | HDF5Examples/C/H5D/h5ex_d_fillval.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5D/h5ex_d_fillval.c b/HDF5Examples/C/H5D/h5ex_d_fillval.c new file mode 100644 index 0000000..15069d2 --- /dev/null +++ b/HDF5Examples/C/H5D/h5ex_d_fillval.c @@ -0,0 +1,155 @@ +/************************************************************ + + This example shows how to set the fill value for a + dataset. The program first sets the fill value to + FILLVAL, creates a dataset with dimensions of DIM0xDIM1, + reads from the uninitialized dataset, and outputs the + contents to the screen. Next, it writes integers to the + dataset, reads the data back, and outputs it to the + screen. Finally it extends the dataset, reads from it, + and outputs the result to the screen. + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_d_fillval.h5" +#define DATASET "DS1" +#define DIM0 4 +#define DIM1 7 +#define EDIM0 6 +#define EDIM1 10 +#define CHUNK0 4 +#define CHUNK1 4 +#define FILLVAL 99 + +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; + hsize_t dims[2] = {DIM0, DIM1}; + hsize_t extdims[2] = {EDIM0, EDIM1}; + hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED}; + hsize_t chunk[2] = {CHUNK0, CHUNK1}; + int wdata[DIM0][DIM1]; /* Write buffer */ + int rdata[DIM0][DIM1]; /* Read buffer */ + int rdata2[EDIM0][EDIM1]; /* Read buffer for extension */ + int fillval; + hsize_t i, j; + + /* + * Initialize data. + */ + for (i = 0; i < DIM0; i++) + for (j = 0; j < DIM1; j++) + wdata[i][j] = i * j - j; + + /* + * Create a new file using the default properties. + */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* + * Create dataspace with unlimited dimensions. + */ + space = H5Screate_simple(2, dims, maxdims); + + /* + * Create the dataset creation property list, and set the chunk + * size. + */ + dcpl = H5Pcreate(H5P_DATASET_CREATE); + status = H5Pset_chunk(dcpl, 2, chunk); + + /* + * Set the fill value for the dataset. + */ + fillval = FILLVAL; + status = H5Pset_fill_value(dcpl, H5T_NATIVE_INT, &fillval); + + /* + * Set the allocation time to "early". This way we can be sure + * that reading from the dataset immediately after creation will + * return the fill value. + */ + status = H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY); + + /* + * Create the dataset using the dataset creation property list. + */ + dset = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT); + + /* + * Read values from the dataset, which has not been written to yet. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata[0]); + + /* + * Output the data to the screen. + */ + printf("Dataset before being written to:\n"); + for (i = 0; i < dims[0]; i++) { + printf(" ["); + for (j = 0; j < dims[1]; j++) + printf(" %3d", rdata[i][j]); + printf("]\n"); + } + + /* + * Write the data to the dataset. + */ + status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata[0]); + + /* + * Read the data back. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata[0]); + + /* + * Output the data to the screen. + */ + printf("\nDataset after being written to:\n"); + for (i = 0; i < dims[0]; i++) { + printf(" ["); + for (j = 0; j < dims[1]; j++) + printf(" %3d", rdata[i][j]); + printf("]\n"); + } + + /* + * Extend the dataset. + */ + status = H5Dset_extent(dset, extdims); + + /* + * Read from the extended dataset. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata2[0]); + + /* + * Output the data to the screen. + */ + printf("\nDataset after extension:\n"); + for (i = 0; i < extdims[0]; i++) { + printf(" ["); + for (j = 0; j < extdims[1]; j++) + printf(" %3d", rdata2[i][j]); + printf("]\n"); + } + + /* + * Close and release resources. + */ + status = H5Pclose(dcpl); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Fclose(file); + + return 0; +} |