GR Programming Model


Every program that uses the GR interface will have these HDF calls in it:
Open a file and obtain a file identifier
Hopen (hopen)

Initialize the GR interface
GRstart (mgstart)

Create or open a GR image
GRcreate (mgcreat) - create a GR image
GRselect (mgselct) - select a GR image

Perform optional operations (reading writing, etc ..)

Terminate access to the GR data set
GRendaccess (mgendac)

Terminate access to the GR interface
GRend (mgend)

Close the file
Hclose (hclose)