C DFACT     SOURCE    GOUNAND   05/12/21    21:18:08     5281           
      FUNCTION DFACT(I)
      IMPLICIT REAL*8 (A-H,O-Z)
      IMPLICIT INTEGER (I-N)
*
* Factorielle I (en réel)
*
      REAL*8 DTMP,DFACT
      INTEGER I,II
      DTMP=1.D0
      DO 1 II=2,I,1
         DTMP=DTMP*DBLE(II)
 1    CONTINUE
      DFACT=DTMP
      END