Help for GF

PURPOSE

	GF   allows   the  user  to  create  FORTRAN or C   like 
	expressions to perform general mathematic operations on 
	one  or more graphics-1 file coordinates.  

TAE COMMAND LINE FORMAT

	GF INP=FILE.GRA PARAMS

	where

	FILE.GRA			  is a random access file.  Since it
					is used for both input and  output, 
					no output file is specified.

	PARAMS		    is   a  standard  VICAR   parameter 
					field.
METHOD

	GF now calls MF, and is provided merely for backward
	compatibility. These two programs are now completely
	interchangeable with the advent of the IBIS-2 subroutine
	library. For more information on the operation of the
	underlying code, see the help for MF. 


RESTRICTIONS

	Maximum number of operations in one execution is 50.
EXAMPLE

	GF INP=MIT FUNCTION=("X5 = X2/X3+100+SQRT(X2)")

	In this example,  X2 is divided by X3 and added to  100 
	plus the square root of X2.   The results are placed in 
	X5.  Further examples of allowable functions follow:

			 FUNCTION=("X5 = .NOT.(X3.AND.X2)")

	logical   operations  are  performed  bitwise  on   the 
	operands

			 FUNCTION=("X5 = X3.LE.X2")

	the  logical values T and F are converted to 1.  and 0. 
	for storage in column X5
			 FUNCTION=("X5 = (X3.LE.X2)*100.")

	the  logical  quantities  1.  and 0.  can  be  used  in 
	arithmetic

			FUNCTION=("X3 = POLY")

	This operation places the polygon number into the third
	coordinate (similar to the INDEX function in program MF)

Original Programmer:  N. D. Ritter	7 July,  1988

Cognizant Programmer:  N. D. Ritter	

Revision:  3				23 November 1994

PARAMETERS: