[svn-r363] Added attribute example code.

2024-11-27 02:10:55 +08:00 · 1998-04-23 17:26:16 -05:00 · 1998-04-23 17:26:16 -05:00 · 11977da23b
commit 11977da23b
parent 5d3d452005
1 changed files with 140 additions and 0 deletions
--- a/examples/Attributes.txt
+++ b/examples/Attributes.txt
@ -0,0 +1,140 @@
+Attribute Examples: 
+
+H5Acreate example: Show how to create an attribute for a dataset and a group
+----------------
+{
+    hid_t file;
+    hid_t group;
+    hid_t dataset;
+    hid_t attr;
+    hid_t dataspace;
+    int32 attr_data;
+    int rank;
+    size_t dimsf[2];
+
+    /* Open the file */
+    file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
+
+    /* Describe the size of the array and create the data space */
+    rank=2;
+    dimsf[0] = H5S_UNLIMITED;
+    dimsf[1] = H5S_UNLIMITED;
+    dataspace = H5Screate_simple(rank, dimsf, NULL); 
+
+    /* Create a dataset */
+    dataset=H5Dcreate(file,"Dataset1",H5T_UINT8,dataspace,H5P_DEFAULT);
+
+    <Write data to first dataset>
+
+    /* Create an attribute for the dataset */
+    attr=H5Acreate(dataset,"Attr1",H5T_INT32,H5S_SCALAR,H5P_DEFAULT);
+
+    /* Write attribute information */
+    H5Awrite(attr,H5T_INT32,&attr_data);
+
+    /* Close attribute */
+    H5Aclose(attr);
+
+    /* Close dataset */
+    H5Dclose(dataset);
+
+    /* Create a group */
+    group=H5Gcreate(file,"/Group One",0);
+
+    /* Create an attribute for the dataset */
+    attr=H5Acreate(group,"Attr1",H5T_INT32,H5S_SCALAR,H5P_DEFAULT);
+
+    /* Write attribute information */
+    H5Awrite(attr,H5T_INT32,&attr_data);
+
+    /* Close attribute */
+    H5Aclose(attr);
+
+    /* Close the group */
+    H5Gclose(group);
+
+    /* Close file */
+    H5Fclose(file);
+}
+
+
+H5Aiterate example: Print all the names of attributes of a dataset, without
+                        any buffers.
+---------------------
+
+herr_t print_names (hid_t loc_id, const char *name, void *opdata)
+{
+    puts (name);
+    return 0;
+}
+
+{
+    H5Aiterate (dataset_or_group_id, NULL, print_names, NULL);
+}
+
+
+H5Aread Example: Attach to an attribute of a dataset and read in attr. data
+----------------
+{
+    hid_t file;
+    hid_t dataset;
+    hid_t attr;
+    int32 attr_data;
+
+    /* Open the file */
+    file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
+
+    /* Open the dataset */
+    dataset=H5Dopen(file,"Dataset1");
+
+    /* Get the OID of the attribute */
+    attr=H5Aopen_name(dataset,"Attr1");
+
+    /* Read attribute */
+    H5Aread(attr,H5T_INT32,attr_data);
+
+    /* Close attribute dataset */
+    H5Aclose(attr);
+
+    /* Close first dataset */
+    H5Dclose(dataset);
+
+    /* Close file */
+    H5Fclose(file);
+}
+
+H5Alink Example: Shows how to share an attribute between two datasets.
+----------------
+{
+    hid_t file;
+    hid_t dataset1, dataset2;
+    hid_t attr;
+
+    /* Open the file */
+    file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
+
+    /* Open the first dataset */
+    dataset1=H5Dopen(file,"Dataset1");
+
+    /* Open the first dataset */
+    dataset2=H5Dopen(file,"Dataset2");
+
+    /* Get the OID of the attribute */
+    attr=H5Aopen_name(dataset1,"Foo");
+
+    /* 
+     * Create an attribute in the second dataset to the attribute in dataset1,
+     * changing the name of the attribute information in dataset2.
+     */
+    H5Alink(dataset2, attr, "Bar");
+
+    /* Close attribute dataset */
+    H5Aclose(attr);
+
+    /* Close datasets */
+    H5Dclose(dataset1);
+    H5Dclose(dataset2);
+
+    /* Close file */
+    H5Fclose(file);
+}