#include "CPP_OPTIONS.h"

      subroutine smooth_correl2D (
     U     fld_in,mask_in,smoothOpNb,mythid)


      IMPLICIT NONE
#include "SIZE.h"
#include "EEPARAMS.h"
#include "GRID.h"
#include "PARAMS.h"
c#include "tamc.h"
#include "smooth.h"

      _RL mask_in(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nR,nSx,nSy)
      _RL fld_in(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy)
      integer smoothOpNb
      integer nbt_in
      character*( 80) fnamegeneric
      integer i,j,bi,bj
      integer itlo,ithi
      integer jtlo,jthi
      integer myThid


      jtlo = mybylo(mythid)
      jthi = mybyhi(mythid)
      itlo = mybxlo(mythid)
      ithi = mybxhi(mythid)


      smoothOpNbCur=smoothOpNb
      nbt_in=wc01_2D_nbt(smoothOpNbCur)/2

cgf later: have an index for the operator number
cfg     and do not forget common block parts (nbt...)

c      write(fnamegeneric(1:80),'(1a)')
C     &    'wc01_2Doperator'
      write(fnamegeneric(1:80),'(1a,i3.3)')
     &    'wc01_2Doperator',smoothOpNbCur
      call mdsreadfield(fnamegeneric,64,'RL',1,
     & diffKhwc01_2D_x,1,mythid)
      call mdsreadfield(fnamegeneric,64,'RL',1,
     & diffKhwc01_2D_y,2,mythid)
      _EXCH_XY_RL ( diffKhwc01_2D_x, myThid )
      _EXCH_XY_RL ( diffKhwc01_2D_y, myThid )


c      write(fnamegeneric(1:80),'(1a)')
c     &    'wc01_2D_filternorm'
      write(fnamegeneric(1:80),'(1a,i3.3)')
     &    'wc01_2Dfilternorm',smoothOpNbCur
      call mdsreadfield(fnamegeneric,64,'RL',1,
     & normFilterwc01_2D,1,mythid)
      _EXCH_XY_RL ( normFilterwc01_2D, myThid )


      DO bj = jtlo,jthi
       DO bi = itlo,ithi
        DO j = 1,sNy
         DO i = 1,sNx 
c division by ~sqrt(volume):
      fld_in(i,j,bi,bj)=fld_in(i,j,bi,bj)
     & *sqrt(recip_rA(i,j,bi,bj))
         ENDDO
        ENDDO
       ENDDO 
      ENDDO


      call smooth_diff2D(fld_in,mask_in,nbt_in,mythid)


       do bj = jtlo,jthi
        do bi = itlo,ithi
         DO j = 1,sNy
          DO i = 1,sNx
c division by ~sqrt(var(filter)):
       fld_in(i,j,bi,bj)=fld_in(i,j,bi,bj)
     & *normFilterwc01_2D(i,j,bi,bj)
          ENDDO
         ENDDO
        ENDDO
       ENDDO

      _EXCH_XY_RL ( fld_in , myThid )
       
      end