if(kdp (i,k) .eq. 1) then                 tmptop = ( finty(i,k,3) - finty(i,k,2) )*rdz(i,k)                 tmpbot = wdz(1,1,     2)*finty(i,k,2) &                        + wdz(2,1,     2)*finty(i,k,3) &                        + wdz(3,1,     2)*finty(i,k,4) &                        + wdz(4,1,     2)*finty(i,k,1)                 fdp(i,k) = finty(i,k,2)*ht (i,k) + tmptop      *dht(i,k) &                          + finty(i,k,3)*hb (i,k) + tmpbot      *dhb(i,k)              else if(kdp (i,k) .eq. kdimm1) then                 tmptop = wdz(1,2,kdimm2)*finty(i,k,4) &                        + wdz(2,2,kdimm2)*finty(i,k,1) &                        + wdz(3,2,kdimm2)*finty(i,k,2) &                        + wdz(4,2,kdimm2)*finty(i,k,3)!!!!!            tmpbot = 0.                 fdp(i,k) = finty(i,k,2)*ht (i,k) + tmptop       *dht(i,k) &                          + finty(i,k,3)*hb (i,k)!!!!!                     + tmpbot      *dhb(i,k)              end if           end do        end do     end if!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!!  Horizontal interpolation only!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!  elseif(lhrzint) then!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!!    50XX loops: an optimized Lagrange cubic/linear algorithm (no!                Hermite interpolator available)!!-----------------------------------------------------------------------!-----------------------------------------------------------------------     if(limdrh) then!! PART 1:  x-interpolation!        do k=1,plev           do i = 1,nlon              ii1 = idp(i,k,1)              ii2 = idp(i,k,2)              ii3 = idp(i,k,3)              ii4 = idp(i,k,4)              jj = jdp(i,k)              kk = kdp(i,k)!! Height level 2!!   Latitude 1:  Linear interpolation!              fintx(i,k,1,2) = fb (ii1  ,kk  ,jj-1)*xl (i,k,1) &                             + fb (ii1+1,kk  ,jj-1)*xr (i,k,1)!!   Latitude 2:  Cubic interpolation!              fxl = (   - 2.*fb (ii2-1,kk  ,jj  ) &                        - 3.*fb (ii2  ,kk  ,jj  ) &                        + 6.*fb (ii2+1,kk  ,jj  ) &                        -    fb (ii2+2,kk  ,jj  ) )*rdx6(jj)              fxr = (        fb (ii2-1,kk  ,jj  ) &                        - 6.*fb (ii2  ,kk  ,jj  ) &                        + 3.*fb (ii2+1,kk  ,jj  ) &                        + 2.*fb (ii2+2,kk  ,jj  ) )*rdx6(jj)!              deli = (       fb (ii2+1,kk  ,jj  ) - &                             fb (ii2  ,kk  ,jj  ) )*rdx(jj)              tmp1 = fac*deli              tmp2 = abs( tmp1 )              if( deli*fxl   .le. 0.0  ) fxl = 0.              if( deli*fxr   .le. 0.0  ) fxr = 0.              if( abs( fxl ) .gt. tmp2 ) fxl = tmp1              if( abs( fxr ) .gt. tmp2 ) fxr = tmp1!              fintx(i,k,2,2) = fb (ii2  ,kk  ,jj  )*hl (i,k,2) &                             + fb (ii2+1,kk  ,jj  )*hr (i,k,2) &                             + fxl*dhl(i,k,2) + fxr*dhr(i,k,2)!!   Latitude 3:  Cubic interpolation!              fxl = (   - 2.*fb (ii3-1,kk  ,jj+1) &                        - 3.*fb (ii3  ,kk  ,jj+1) &                        + 6.*fb (ii3+1,kk  ,jj+1) &                        -    fb (ii3+2,kk  ,jj+1) )*rdx6(jj+1)              fxr = (        fb (ii3-1,kk  ,jj+1) &                        - 6.*fb (ii3  ,kk  ,jj+1) &                        + 3.*fb (ii3+1,kk  ,jj+1) &                        + 2.*fb (ii3+2,kk  ,jj+1) )*rdx6(jj+1)!              deli = (       fb (ii3+1,kk  ,jj+1) - &                             fb (ii3  ,kk  ,jj+1) )*rdx(jj+1)              tmp1 = fac*deli              tmp2 = abs( tmp1 )              if( deli*fxl   .le. 0.0  ) fxl = 0.              if( deli*fxr   .le. 0.0  ) fxr = 0.              if( abs( fxl ) .gt. tmp2 ) fxl = tmp1              if( abs( fxr ) .gt. tmp2 ) fxr = tmp1!              fintx(i,k,3,2) = fb (ii3  ,kk  ,jj+1)*hl (i,k,3) &                             + fb (ii3+1,kk  ,jj+1)*hr (i,k,3) &                             + fxl*dhl(i,k,3) + fxr*dhr(i,k,3)!!   Latitude 4:  Linear interpolation!              fintx(i,k,4,2) = fb (ii4  ,kk  ,jj+2)*xl (i,k,4) &                             + fb (ii4+1,kk  ,jj+2)*xr (i,k,4)           end do        end do!! PART 2:  y-derivatives!        jmin =  1000000        jmax = -1000000        do k=1,plev           do i = 1,nlon              if(jdp(i,k) .lt. jmin) jmin = jdp(i,k)              if(jdp(i,k) .gt. jmax) jmax = jdp(i,k)           end do        end do!! Loop over departure latitudes!        icount = 0        do jdpval = jmin,jmax           do k=1,plev              call wheneq(nlon    ,jdp(1,k),1       ,jdpval  , &                          indx    ,nval    )              icount = icount + nval!! y derivatives at the inner height levels (kk = 2,3) needed for! z-interpolation!              do kk  = 2,2                 do ii = 1,nval                    i = indx(ii)                    fbot(i,k,kk) = lbasdy(1,1,jdpval)*fintx(i,k,1,kk) &                                 + lbasdy(2,1,jdpval)*fintx(i,k,2,kk) &                                 + lbasdy(3,1,jdpval)*fintx(i,k,3,kk) &                                 + lbasdy(4,1,jdpval)*fintx(i,k,4,kk)                    ftop(i,k,kk) = lbasdy(1,2,jdpval)*fintx(i,k,1,kk) &                                 + lbasdy(2,2,jdpval)*fintx(i,k,2,kk) &                                 + lbasdy(3,2,jdpval)*fintx(i,k,3,kk) &                                 + lbasdy(4,2,jdpval)*fintx(i,k,4,kk)                 end do              end do           end do        end do        if (icount.ne.nlon*plev) then           write(*,*)'SLTINT:  Did not complete computations for all departure points'           call endrun        end if!! Apply SCM0 limiter to derivative estimates.!        do kk  = 2,2           do k=1,plev              do i = 1,nlon                 deli = ( fintx(i,k,3,kk) - fintx(i,k,2,kk) )*rdphi(i,k)                 tmp1 = fac*deli                 tmp2 = abs( tmp1 )                 if( deli*fbot(i,k,kk)   .le. 0.0  ) fbot(i,k,kk) = 0.                 if( deli*ftop(i,k,kk)   .le. 0.0  ) ftop(i,k,kk) = 0.                 if( abs( fbot(i,k,kk) ) .gt. tmp2 ) fbot(i,k,kk) = tmp1                 if( abs( ftop(i,k,kk) ) .gt. tmp2 ) ftop(i,k,kk) = tmp1              end do           end do        end do!! PART 3:  y-interpolants!        do k=1,plev           do i = 1,nlon              fdp(i,k) = fintx(i,k,2,2)*hs (i,k) + fbot (i,k,2)*dhs(i,k) &                       + fintx(i,k,3,2)*hn (i,k) + ftop (i,k,2)*dhn(i,k)           end do        end do     endif!     if( .not. limdrh ) then!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!!    60XX loops: Hermite cubic/linear interpolation in the horizontal!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!        do k=1,plev           do i=1,nlon              ii1 = idp(i,k,1)              ii2 = idp(i,k,2)              ii3 = idp(i,k,3)              ii4 = idp(i,k,4)              jj = jdp(i,k)              kk = kdp(i,k)!! x-interpolants for the 4 latitudes!              f1 = fb(ii1+1,kk,jj-1)*xr   (i,k,1) &                 + fb(ii1  ,kk,jj-1)*xl   (i,k,1)              f2 = fb(ii2-1,kk,jj  )*wgt1x(i,k,2) &                 + fb(ii2  ,kk,jj  )*wgt2x(i,k,2) &                 + fb(ii2+1,kk,jj  )*wgt3x(i,k,2) &                 + fb(ii2+2,kk,jj  )*wgt4x(i,k,2)              f3 = fb(ii3-1,kk,jj+1)*wgt1x(i,k,3) &                 + fb(ii3  ,kk,jj+1)*wgt2x(i,k,3) &                 + fb(ii3+1,kk,jj+1)*wgt3x(i,k,3) &                 + fb(ii3+2,kk,jj+1)*wgt4x(i,k,3)              f4 = fb(ii4+1,kk,jj+2)*xr   (i,k,4) &                 + fb(ii4  ,kk,jj+2)*xl   (i,k,4)!! y-interpolant!              fdp(i,k) = f1*wgt1y(i,k) + f2*wgt2y(i,k) + &                         f3*wgt3y(i,k) + f4*wgt4y(i,k)           end do        end do     end if!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!!  Vertical interpolation only!!    70XX loops: an optimized Lagrange cubic/linear algorithm (no!                Hermite interpolator available)!!-----------------------------------------------------------------------!-----------------------------------------------------------------------!  else if(lvrtint) then     if(limdrh .or. limdrv) then        write(6,*) 'SLTINT:  ERROR:  this routine does not provide '        write(6,*) 'shape preserving capability for vertical-only'        write(6,*) ' interpolation'        call endrun     end if     do k=1,plev        do i=1,nlon           kk = kkdp(i,k)           ii = i1+i-1           fdp(i,k) = fb(ii,kk-1,jcen)*wgt1z(i,k) &                    + fb(ii,kk  ,jcen)*wgt2z(i,k) &                    + fb(ii,kk+1,jcen)*wgt3z(i,k) &                    + fb(ii,kk+2,jcen)*wgt4z(i,k)        end do     end do!! IF the departure point is in either the top or bottom interval of the! model grid:  THEN perform Hermite cubic interpolation.  The following! overwrites some results from the previous loop.!     do k=1,plev        do i=1,nlon           ii = i1+i-1           if(kdp (i,k) .eq. 1) then!!!!!         tmptop   = 0.              tmpbot   = wdz(1,1,     2)*fb(ii,     1,jcen) &                       + wdz(2,1,     2)*fb(ii,     2,jcen) &                       + wdz(3,1,     2)*fb(ii,     3,jcen) &                       + wdz(4,1,     2)*fb(ii,     4,jcen)              fdp(i,k) = fb(ii,1     ,jcen)*ht (i,k) &                    &  + fb(ii,2     ,jcen)*hb (i,k) &                    &  + tmpbot            *dhb(i,k)!!!!!               &  + tmptop            *dht(i,k)           else if(kdp (i,k) .eq. kdimm1) then              tmptop = wdz(1,2,kdimm2)*fb(ii,kdimm3,jcen) &                     + wdz(2,2,kdimm2)*fb(ii,kdimm2,jcen) &                     + wdz(3,2,kdimm2)*fb(ii,kdimm1,jcen) &                     + wdz(4,2,kdimm2)*fb(ii,kdim  ,jcen)!!!!!         tmpbot = 0.              fdp(i,k) = fb(ii,kdimm1,jcen)*ht (i,k) &                       + tmptop            *dht(i,k) &                       + fb(ii,kdim  ,jcen)*hb (i,k)!!!!!                  + tmpbot            *dhb(i,k)           end if        end do     end do  else     write(6,*) 'SLTINT:  Error: must specify at least one of "lhr', &          'zint" or "lvrtint" to be ".true."'     call endrun  end if!  returnend subroutine sltint