SUBROUTINE GAUSSIAN 1,1
      IMPLICIT NONE
      include 'champ.cdk'


      REAL zx,zy

          DO IW = 1, N/2 + 1
           zx = (IW -1)* delx
            DO JW = 1, N/2+1
              zy = (JW - 1) * delx
              F(IW,JW) = exp(- (zx**2 + zy**2)/(2*D**2) )
            END DO
            DO JW = N/2+2,N
              zy = (JW - 1 -N)*delx
              F(IW,JW) = exp(- (zx**2 + zy**2)/(2*D**2) )
            END DO
          END DO
          DO IW = N/2+2,N
            zx = (IW -1-N)* delx
            DO JW = 1,N/2+1
             zy = (JW - 1) * delx
             F(IW,JW) = exp(- (zx**2 + zy**2)/(2*D**2) )
            END DO
            DO JW = N/2+2,N
             zy = (JW - 1 - N)*delx
             F(IW,JW) = exp(- (zx**2 + zy**2)/(2*D**2) )
            END DO
          END DO

          DO IW=1,N
          DO JW=1,N
            F(IW,JW) = N**2 * F(IW,JW)
          ENDDO
          ENDDO 
       CALL RK(F,Ftilde,KTX,KTY,IKTX,IKTY,N,N2,LWRK,
     .                  FF1,FF2,FF3,WORK,TRIGS,IFAX,ZI)

      END