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author | Elena Pourmal <epourmal@hdfgroup.org> | 1998-02-08 18:38:20 (GMT) |
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committer | Elena Pourmal <epourmal@hdfgroup.org> | 1998-02-08 18:38:20 (GMT) |
commit | 35e7a062e26c1a65e571202a6fda0b475e42da00 (patch) | |
tree | 2d1e936dae47e19b50b8cfc04998a1b01193bcaa /examples/h5_compound.c | |
parent | 08cd0cc138444f5981c4b84aaee4c6499bf1873c (diff) | |
download | hdf5-35e7a062e26c1a65e571202a6fda0b475e42da00.zip hdf5-35e7a062e26c1a65e571202a6fda0b475e42da00.tar.gz hdf5-35e7a062e26c1a65e571202a6fda0b475e42da00.tar.bz2 |
[svn-r229] New examples have been created in the examples directory:
h5_write.c - stores INT array as INT32 little endian dataset in the HDF5 file.
h5_read.c - gets info about the dataset;
reads hyperslab from the dataset in the file into
2-dim slice of the 3 dimensional array.
h5_compund.c - creates compound dataset and writes it to the file;
reads subsets of the dataset.
h5_extend_write.c - writes extendable dataset.
h5_extend_read.c - gets info about the dataset;
reads dataset and one of the chunks.
Diffstat (limited to 'examples/h5_compound.c')
-rw-r--r-- | examples/h5_compound.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/examples/h5_compound.c b/examples/h5_compound.c new file mode 100644 index 0000000..a5ad77b --- /dev/null +++ b/examples/h5_compound.c @@ -0,0 +1,155 @@ +/* + * This example shows how to create a compound data type, + * write an array which has the compound data type to the file, + * and read back fields' subsets. + */ + +#include "hdf5.h" + +#define FILE "SDScompound.h5" +#define DATASETNAME "ArrayOfStructures" +#define LENGTH 10 +#define RANK 1 + +main() + +{ + + +/* First structure and dataset*/ +typedef struct s1_t { + int a; + float b; + double c; +} s1_t; +s1_t s1[LENGTH]; +hid_t s1_tid; /* File datatype hadle */ + +/* Second structure (subset of s1_t) and dataset*/ +typedef struct s2_t { + double c; + int a; +} s2_t; +s2_t s2[LENGTH]; +hid_t s2_tid; /* Memory datatype handle */ + +/* Third "structure" ( will be used to read float field of s1) */ +hid_t s3_tid; /* Memory datatype handle */ +float s3[LENGTH]; + +int i; +hid_t file, datatype, dataset, space; /* Handles */ +herr_t status; +size_t dim[] = {LENGTH}; /* Dataspace dimensions */ + +H5T_class_t class; +size_t size; + +/* + * Initialize the data + */ + for (i = 0; i< LENGTH; i++) { + s1[i].a = i; + s1[i].b = i*i; + s1[i].c = 1./(i+1); +} + +/* + * Create the data space. + */ +space = H5Pcreate_simple(RANK, dim, NULL); + +/* + * Create the file. + */ +file = H5Fcreate(FILE, H5ACC_OVERWRITE, H5C_DEFAULT, H5C_DEFAULT); + +/* + * Create the memory data type. + */ +s1_tid = H5Tcreate (H5T_COMPOUND, sizeof(s1_t)); +status = H5Tinsert(s1_tid, "a_name", HPOFFSET(s1, a), H5T_NATIVE_INT); +status = H5Tinsert(s1_tid, "c_name", HPOFFSET(s1, c), H5T_NATIVE_DOUBLE); +status = H5Tinsert(s1_tid, "b_name", HPOFFSET(s1, b), H5T_NATIVE_FLOAT); + +/* + * Create the dataset. + */ +dataset = H5Dcreate(file, DATASETNAME, s1_tid, space, H5C_DEFAULT); + +/* + * Wtite data to the dataset; + */ +status = H5Dwrite(dataset, s1_tid, H5P_ALL, H5P_ALL, H5C_DEFAULT, s1); + +/* + * Release resources + */ +H5Tclose(s1_tid); +H5Pclose(space); +H5Dclose(dataset); +H5Fclose(file); + +/* + * Open the file and the dataset. + */ +file = H5Fopen(FILE, H5ACC_DEFAULT, H5C_DEFAULT); + +dataset = H5Dopen(file, DATASETNAME); + +/* + * Create a data type for s2 + */ +s2_tid = H5Tcreate(H5T_COMPOUND, sizeof(s2_t)); + +status = H5Tinsert(s2_tid, "c_name", HPOFFSET(s2, c), H5T_NATIVE_DOUBLE); +status = H5Tinsert(s2_tid, "a_name", HPOFFSET(s2, a), H5T_NATIVE_INT); + +/* + * Read two fields c and a from s1 dataset. Fields iin the file + * are found by their names "c_name" and "a_name". + */ +status = H5Dread(dataset, s2_tid, H5P_ALL, H5P_ALL, H5C_DEFAULT, s2); + +/* + * Display the fields + */ +printf("\n"); +printf("Field c : \n"); +for( i = 0; i < LENGTH; i++) printf("%.4f ", s2[i].c); +printf("\n"); + +printf("\n"); +printf("Field a : \n"); +for( i = 0; i < LENGTH; i++) printf("%d ", s2[i].a); +printf("\n"); + +/* + * Create a data type for s3. + */ +s3_tid = H5Tcreate(H5T_COMPOUND, sizeof(float)); + +status = H5Tinsert(s3_tid, "b_name", 0, H5T_NATIVE_FLOAT); + +/* + * Read field b from s1 dataset. Field in the file is found by its name. + */ +status = H5Dread(dataset, s3_tid, H5P_ALL, H5P_ALL, H5C_DEFAULT, s3); + +/* + * Display the field + */ +printf("\n"); +printf("Field b : \n"); +for( i = 0; i < LENGTH; i++) printf("%.4f ", s3[i]); +printf("\n"); + +/* + * Release resources + */ +H5Tclose(s2_tid); +H5Tclose(s3_tid); +H5Dclose(dataset); +H5Pclose(space); +H5Fclose(file); +} |