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GRstart/mgstart

intn GRstart(int32 file_id)
file_id

IN:

File identifier returned by Hopen.

Purpose

Initializes the general raster interface.

Return value

Returns a general raster interface identifier if successful and FAIL (or -1) otherwise.

Description

This routine is used with the GRend routine to define the extent of a general raster interface session. As with the start routines in the other interfaces, GRstart initializes the internal interface structures needed for the remaining GR routines. Use the general purpose routines Hopen and Hclose to manage file access. The GR routines will not open and close HDF files.

Example

This example illustrates the use of GRstart and GRend in initializing and terminating a GR interface session.

     #include "hdf.h"
     int32 gr_id, file_id, stat;

     file_id = Hopen("myfile", DFACC_WRITE, 0);
     gr_id = GRstart(file_id);
       ...
     stat = GRend(gr_id);
     Hclose(file_id); 
FORTRAN

integer function mgstart(file_id)

integer file_id



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HDF User's Reference Manual, Draft 06/09/97, NCSA HDF Development Group.