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Diffstat (limited to 'HDF5Examples/C/H5D/h5ex_d_extern.c')
-rw-r--r-- | HDF5Examples/C/H5D/h5ex_d_extern.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5D/h5ex_d_extern.c b/HDF5Examples/C/H5D/h5ex_d_extern.c new file mode 100644 index 0000000..ac78fd0 --- /dev/null +++ b/HDF5Examples/C/H5D/h5ex_d_extern.c @@ -0,0 +1,128 @@ +/************************************************************ + + This example shows how to read and write data to an + external dataset. The program first writes integers to an + external dataset with dataspace dimensions of DIM0xDIM1, + then closes the file. Next, it reopens the file, reads + back the data, and outputs the name of the external data + file and the data to the screen. + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_d_extern.h5" +#define EXTERNAL "h5ex_d_extern.data" +#define DATASET "DS1" +#define DIM0 4 +#define DIM1 7 +#define NAME_BUF_SIZE 32 + +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}; + char name[NAME_BUF_SIZE]; + int wdata[DIM0][DIM1]; /* Write buffer */ + int rdata[DIM0][DIM1]; /* Read buffer */ + 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. 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, set the external + * file. + */ + dcpl = H5Pcreate(H5P_DATASET_CREATE); + status = H5Pset_external(dcpl, EXTERNAL, 0, H5F_UNLIMITED); + + /* + * Create the external dataset. + */ + dset = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT); + + /* + * Write the data to the dataset. + */ + status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, 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 dataset creation property list. + */ + dcpl = H5Dget_create_plist(dset); + + /* + * Retrieve and print the name of the external file. Here we + * manually set the last field in name to null, in case the name of + * the file is longer than the buffer. + */ + status = H5Pget_external(dcpl, 0, NAME_BUF_SIZE, name, NULL, NULL); + name[NAME_BUF_SIZE - 1] = '\0'; + printf("%s is stored in file: %s\n", DATASET, name); + + /* + * 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("%s:\n", DATASET); + 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 = H5Fclose(file); + + return 0; +} |