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);
+}