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141 lines
3.1 KiB
Plaintext
141 lines
3.1 KiB
Plaintext
Attribute Examples:
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H5Acreate example: Show how to create an attribute for a dataset and a group
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----------------
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{
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hid_t file;
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hid_t group;
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hid_t dataset;
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hid_t attr;
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hid_t dataspace;
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int32 attr_data;
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int rank;
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size_t dimsf[2];
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/* Open the file */
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file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
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/* Describe the size of the array and create the data space */
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rank=2;
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dimsf[0] = H5S_UNLIMITED;
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dimsf[1] = H5S_UNLIMITED;
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dataspace = H5Screate_simple(rank, dimsf, NULL);
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/* Create a dataset */
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dataset=H5Dcreate(file,"Dataset1",H5T_UINT8,dataspace,H5P_DEFAULT);
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<Write data to first dataset>
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/* Create an attribute for the dataset */
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attr=H5Acreate(dataset,"Attr1",H5T_INT32,H5S_SCALAR,H5P_DEFAULT);
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/* Write attribute information */
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H5Awrite(attr,H5T_INT32,&attr_data);
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/* Close attribute */
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H5Aclose(attr);
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/* Close dataset */
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H5Dclose(dataset);
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/* Create a group */
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group=H5Gcreate(file,"/Group One",0);
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/* Create an attribute for the dataset */
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attr=H5Acreate(group,"Attr1",H5T_INT32,H5S_SCALAR,H5P_DEFAULT);
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/* Write attribute information */
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H5Awrite(attr,H5T_INT32,&attr_data);
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/* Close attribute */
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H5Aclose(attr);
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/* Close the group */
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H5Gclose(group);
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/* Close file */
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H5Fclose(file);
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}
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H5Aiterate example: Print all the names of attributes of a dataset, without
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any buffers.
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---------------------
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herr_t print_names (hid_t loc_id, const char *name, void *opdata)
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{
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puts (name);
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return 0;
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}
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{
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H5Aiterate (dataset_or_group_id, NULL, print_names, NULL);
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}
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H5Aread Example: Attach to an attribute of a dataset and read in attr. data
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----------------
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{
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hid_t file;
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hid_t dataset;
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hid_t attr;
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int32 attr_data;
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/* Open the file */
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file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
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/* Open the dataset */
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dataset=H5Dopen(file,"Dataset1");
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/* Get the OID of the attribute */
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attr=H5Aopen_name(dataset,"Attr1");
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/* Read attribute */
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H5Aread(attr,H5T_INT32,attr_data);
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/* Close attribute dataset */
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H5Aclose(attr);
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/* Close first dataset */
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H5Dclose(dataset);
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/* Close file */
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H5Fclose(file);
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}
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H5Alink Example: Shows how to share an attribute between two datasets.
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----------------
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{
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hid_t file;
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hid_t dataset1, dataset2;
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hid_t attr;
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/* Open the file */
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file=H5Fopen("example.h5", H5F_ACC_RDWR, H5P_DEFAULT);
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/* Open the first dataset */
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dataset1=H5Dopen(file,"Dataset1");
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/* Open the first dataset */
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dataset2=H5Dopen(file,"Dataset2");
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/* Get the OID of the attribute */
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attr=H5Aopen_name(dataset1,"Foo");
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/*
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* Create an attribute in the second dataset to the attribute in dataset1,
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* changing the name of the attribute information in dataset2.
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*/
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H5Alink(dataset2, attr, "Bar");
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/* Close attribute dataset */
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H5Aclose(attr);
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/* Close datasets */
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H5Dclose(dataset1);
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H5Dclose(dataset2);
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/* Close file */
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H5Fclose(file);
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}
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