!copyright (C) 2001  MSC-RPN COMM  %%%RPNPHY%%%
*** FUNCTION GAMMA2

      FUNCTION GAMMA2 (X) 6
#include "impnone.cdk"
* 
      REAL GAMMA2,X
*
*Author
*          Stephane Belair  July 1991
*
*Revision
* 001      Bernard Bilodeau (March 2002) - Rename function to eliminate
*                                          name conflict
*
*Object
*          to calculate value using the gamma function
*          given X
* 
*Arguments
*
*          - Input -
* X        input to gamma function
*
*          - Output -
* GAMMA2   result of gamma function of X
*
*Notes
*
**
      X = X-1 
* 
      GAMMA2 = 
     1       (2.0*3.1416*X)**0.5* X**X *EXP(-X) * 
     1       ( 1.0 + 1.0/(12.0*X) +1.0/(288.0*X*X) -
     1         139./(51840.*X*X*X) )
*
      RETURN
      END