*
* $Id: funran.F,v 1.1.1.1 1996/04/01 15:02:57 mclareni Exp $
*
* $Log: funran.F,v $
* Revision 1.1.1.1  1996/04/01 15:02:57  mclareni
* Mathlib gen
*
*
#include "gen/pilot.h"
      SUBROUTINE FUNRAN(ARRAY,XRAN)
C         GENERATION OF RANDOM NUMBERS IN ANY GIVEN DISTRIBUTION, BY
C         4-POINT INTERPOLATION IN THE INVERSE CUMULATIVE DISTR.
C         WHICH WAS PREVIOUSLY GENERATED BY FUNPRE
      SAVE RBUF, IBUF, GAP, GAPINV
      COMMON/FUNINT/X
      DIMENSION ARRAY(100)
      DIMENSION RBUF(20)
      DATA IBUF/20/
      DATA GAP,GAPINV/.0101010101,99./
C
      IF (IBUF .LT. 20)  GO TO 10
      CALL NRAN(RBUF,020)
      IBUF = 0
   10 IBUF = IBUF + 1
      X = RBUF(IBUF)
      J = INT(  X    *GAPINV) + 1
      J = MAX(J,2)
      J = MIN(J,98)
      P = (   X -GAP*(J-1)) * GAPINV
      A = (P+1.0) * ARRAY(J+2) - (P-2.0)*ARRAY(J-1)
      B = (P-1.0) * ARRAY(J) - P * ARRAY(J+1)
      XRAN = A*P *(P-1.0) *0.16666667  + B * (P+1.0) * (P-2.0) * 0.5
      RETURN
      END