subroutine hetrfm1(n,x,y,a,grw,iop)
******************************************
*     1-D transform in Serie of Hermite FUNCTIONS !
* Input: a,grw: output from heinit.f
*     iop=1: spectral to physics
*     iop=0: physics to spectral
*      x: sequence to be transformed
* Output: y: transformed sequence
*****************************************      
      implicit double precision (a-h,o-z)
      dimension x(n),y(n),a(n,0:n-1),grw(n)
      if (iop.eq.0) then
         do j=1,n
            x(j)=x(j)*grw(j)
         enddo
         call dgemv('t',n,n,1.d0,a,n,x,1,0.d0,y,1)
      else
         call dgemv('n',n,n,1.d0,a,n,x,1,0.d0,y,1)
      endif

      return
      end