ri_id

IN:

Raster image identifier returned by GRselect or GRcreate

	Purpose	Maps a raster image identifier to a reference number.
	Return value	Returns the reference number of the raster image if successful and 0 otherwise.
	Description	GRidtoref returns the reference number of the raster image identified by the parameter ri_id.
		This routine is commonly used for the purpose of annotating the raster image or including the raster image within a vgroup.

	FORTRAN	integer function mgid2rf(ri_id)
		integer ri_id