Getting Information from a Vgroup


Contents:



How to Get Information from a Vgroup

Following are some of the functions you can use to get information on a Vgroup: (Functions in bold are included in the example program for this tutorial.)

Sample Program

The following program opens the HDF file, vg_sd1.hdf (for FORTRAN, vg_sd1f.hdf), and reads every Vgroup in this file, listing all tag/ref pairs in each Vgroup (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.

Following is a detailed review of what this program does:

Following is what this program outputs:
 Vgroup Name: MyVgroup
 Vgroup Class: MyClass
 Found tag =   720 ref =   2 at position   1
 
 Vgroup Name: fakeDim0
 Vgroup Class: Dim0.0
 Found tag =   1962 ref =   4 at position   1
 Found tag =   1962 ref =   5 at position   2
 
 Vgroup Name: sd1Dim0
 Vgroup Class: Var0.0
 Found tag =   1965 ref =   6 at position   1
 Found tag =   106 ref =   7 at position   2
 Found tag =   701 ref =   7 at position   3
 Found tag =   720 ref =   2 at position   4
 
 Vgroup Name: vg_sd1f.hdf
 Vgroup Class: CDF0.0
 Found tag =   1965 ref =   6 at position   1
 Found tag =   1965 ref =   8 at position   2
 
NOTE: Another way to have done this would have been to use the Vinquire (vfinq) function. In this case you would not need to call Vgetname (vfgnam) since the Vinquire (vfinq) passes back the Vgroup name in addition to the number of entries in a Vgroup.

Download Sample Program (optional)

Programs used in this tutorial: [Compiling a program]