c
c------------------------------------------------------------------
c Begin file /home/sting/foster/timesdif/recpert.f
c------------------------------------------------------------------
c
      subroutine recpert(fld,pnt)
c
c Recover perturbed selected fields:
c 
c On input:
c   fld contains differences at selected fields
c   pnt contains control at all fields
c On output:
c   fld contains perturbed at selected fields
c   pnt is unchanged
c
c d = (p-c) / c * 100. ==> p = d/100.*c + c where d=diff, p=pert, c=cntr
c
      include 'gettime.h'
      include 'timesdif.h'
      dimension fld(imx,kmx,jmx,nplfld),pnt(imx,kmx,jmx,ntimefld)
c
      ixp = 0
      do ip=1,ntimefld
        if (ipltime(ip).le.0) goto 100
        ixp = ixp+1
        if (wtime(ip).gt.0.) then
          do j=1,jmx
            do k=1,kmx
              do i=1,imx
                if (pnt(i,k,j,ip).ne.cpspval.and.
     +            fld(i,k,j,ixp).ne.cpspval) then
                  fld(i,k,j,ixp) = fld(i,k,j,ixp)/100.*pnt(i,k,j,ip) +
     +                             pnt(i,k,j,ip)
                else
                  fld(i,k,j,ixp) = cpspval
                endif
              enddo
            enddo
          enddo
        else
          fld(:,:,:,ixp) = fld(:,:,:,ixp) + pnt(:,:,:,ip)
        endif

 100    continue
      enddo
c
      return
      end