subroutine wgrad(a,c,d)
c
c.... find (c,d)=grad a
c
      implicit none
      include 'itg.par'
      include 'itg.cmn'
c     include 'post.cmn'
      real a(lz,mz,nz,nspecz),c(lz,mz,nz,nspecz),
     * d(lz,mz,nz,nspecz)
c
      integer l,m,n,mr

      do 2 n=1,nd
      do 2 m=1,md
      mr=mrr(m,n)
      c(1,m,n,1)=(a(2,m,n,1)-a(1,m,n,1))/r(2)
      d(1,m,n,1)=mr/y0*a(1,m,n,1)
      c(ld,m,n,1)=(a(ld,m,n,1)-a(ldb,m,n,1))/(0.5*dr(ld))
      d(ld,m,n,1)=mr/y0*a(ld,m,n,1)
      do 2 l=2,ldb
      c(l,m,n,1)=(a(l+1,m,n,1)-a(l-1,m,n,1))/dr(l)
      d(l,m,n,1)=mr/y0*a(l,m,n,1)
    2 continue
      return
      end