Writing Annotations


Contents:



How to Write Annotations

Typical functions that you would use to write an annotation are as follows:

Sample Program

The an_write program is a sample program for writing out the four types of annotations. You can either download the C or FORTRAN program at the end, or just take a look at the HTML version, with the HDF calls highlighted: If you have downloaded this program, then you can compile and run it. It creates an HDF file called an.hdf. You can view the contents of the HDF file that gets created by this program, in the next section, "Contents of HDF File Created".

Following is a detailed review of what this program does:


Contents of HDF File Created

You can view the contents of an.hdf, using the hdp command. Following is the output you would get by examining the file with hdp list -a -n an.hdf:
File: an.hdf

File library version: Major= 4, Minor=1, Release=1
String=NCSA HDF Version 4.1 Release 1, February 21, 1997
File Label #0: This is a file label.      
File description #0: This is a file description.
   no             tagname     tag     ref  index_by_tag
    0  Version Descriptor      30       1           0
    1     File Identifier     100       1           0
    2    File Description     101       1           0
    3       Data Id Label     104       1           0
    4  Data Id Annotation     105       1           0
    5              Vgroup    1965       2           0
    Name/Label=This is a data label.      
   Description=This is a data description.

Download Sample Program (optional)

Programs used in this tutorial: [Compiling a program]