summaryrefslogtreecommitdiffstats
path: root/HDF5Examples/C/H5D/h5ex_d_fillval.c
diff options
context:
space:
mode:
Diffstat (limited to 'HDF5Examples/C/H5D/h5ex_d_fillval.c')
-rw-r--r--HDF5Examples/C/H5D/h5ex_d_fillval.c155
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;
+}