#include "EXF_OPTIONS.h" CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C Flux Coupler using C C Bilinear interpolation of forcing fields C C C C B. Cheng (12/2002) C C C C added Bicubic (bnc 1/2003) C C C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC real*8 function lagran(i,x,a,sp) INTEGER i,k,sp _RS x real*8 a(4) real*8 numer,denom numer = 1.D0 denom = 1.D0 do k=1,sp if ( k .ne. i) then denom = denom*(a(i) - a(k)) numer = numer*(x - a(k)) endif enddo lagran = numer/denom return end SUBROUTINE exf_interp( I infile, I filePrec, O arrayout, I irecord, xG, yG, I lon_0, lon_inc, I lat_0, lat_inc, I nx_in, ny_in, method, mythid) implicit none C infile = name of the input file (direct access binary) C filePrec = file precicision (currently not used, assumes real*4) C arrout = output arrays (different for each processor) C irecord = record number in global file C xG,yG = coordinates for output grid C lon_0, lat_0 = lon and lat of sw corner of global input grid C lon_inc = scalar x-grid increment C lat_inc = vector y-grid increments C nx_in, ny_in = input x-grid and y-grid size C method = 1 for bilinear 2 for bicubic C mythid = thread id C #include "SIZE.h" #include "EEPARAMS.h" #include "PARAMS.h" C subroutine variables character*(*) infile integer filePrec, irecord, nx_in, ny_in _RL arrayout(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RS xG_in (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RS yG (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL lon_0, lon_inc _RL lat_0, lat_inc(ny_in-1) integer method, mythid C local variables real*8 ne_fac,nw_fac,se_fac,sw_fac integer e_ind(snx,sny),w_ind(snx,sny) integer n_ind(snx,sny),s_ind(snx,sny) real*8 px_ind(4), py_ind(4), ew_val(4) external lagran real*8 lagran real*4 arrayin(-1:nx_in+2 , -1:ny_in+2) real*8 x_in (-1:nx_in+2), y_in(-1:ny_in+2) integer i, j, k, l, js, bi, bj, sp, interp_unit _RS xg(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) ! nomalize xg do bj=myByLo(myThid),myByHi(myThid) do bi=myBxLo(myThid),myBxHi(myThid) do j=1-OLy,sNy+OLy do i=1-OLx,sNx+OLx xg(i,j,bi,bj) = xg_in(i,j,bi,bj) xg(i,j,bi,bj) = mod(xg(i,j,bi,bj),360.) if ( xg(i,j,bi,bj) .lt. 0. ) & xg(i,j,bi,bj) = 360.+xg(i,j,bi,bj) enddo enddo enddo enddo call exf_interp_read( I infile, I filePrec, O arrayin, I irecord, xG, yG, I lon_0, lon_inc, I lat_0, lat_inc, I nx_in, ny_in, method, mythid) _BARRIER C _BEGIN_MASTER( myThid ) C setup input grid do i=-1,nx_in+2 x_in(i) = lon_0 + (i-1.)*lon_inc x_in(i) = mod(x_in(i),360.) if ( x_in(i) .lt. 0. ) & x_in(i) = 360.+x_in(i) enddo y_in(0) = lat_0 - lat_inc(1) y_in(-1)= lat_0 - 2.*lat_inc(1) y_in(1) = lat_0 do j=2,ny_in y_in(j) = y_in(j-1) + lat_inc(j-1) enddo y_in(ny_in+1) = y_in(ny_in) + lat_inc(ny_in-1) y_in(ny_in+2) = y_in(ny_in) + 2.*lat_inc(ny_in-1) C enlarge boundary do j=1,ny_in arrayin(0,j) = arrayin(nx_in,j) arrayin(-1,j) = arrayin(nx_in-1,j) arrayin(nx_in+1,j) = arrayin(1,j) arrayin(nx_in+2,j) = arrayin(2,j) enddo do i=-1,nx_in+2 arrayin(i,0) = arrayin(i,1) arrayin(i,-1) = arrayin(i,1) arrayin(i,ny_in+1) = arrayin(i,ny_in) arrayin(i,ny_in+2) = arrayin(i,ny_in) enddo C _END_MASTER( myThid ) do bj = mybylo(mythid), mybyhi(mythid) do bi = mybxlo(mythid), mybxhi(mythid) C check validity of input/output coordinates #ifdef ALLOW_DEBUG if ( debugLevel .ge. debLevB ) then do i=1,snx do j=1,sny if ( xG(i,j,bi,bj) .lt. x_in(0) .or. & xG(i,j,bi,bj) .ge. x_in(nx_in+1) .or. & yG(i,j,bi,bj) .lt. y_in(0) .or. & yG(i,j,bi,bj) .ge. y_in(ny_in+1) ) then print*,'ERROR in S/R EXF_INTERP:' print*,' input grid must encompass output grid.' print*,'i,j,bi,bj' ,i,j,bi,bj print*,'xG,yG' ,xG(i,j,bi,bj),yG(i,j,bi,bj) print*,'nx_in,ny_in' ,nx_in ,ny_in print*,'x_in(0,nx_in+1)',x_in(0) ,x_in(nx_in+1) print*,'y_in(0,ny_in+1)',y_in(0) ,y_in(ny_in+1) STOP ' ABNORMAL END: S/R EXF_INTERP' endif enddo enddo endif #endif /* ALLOW_DEBUG */ C compute interpolation indices do i=1,snx do j=1,sny if (xG(i,j,bi,bj)-x_in(1) .ge. 0.) then w_ind(i,j) = int((xG(i,j,bi,bj)-x_in(1))/lon_inc) + 1 else w_ind(i,j) = int((xG(i,j,bi,bj)-x_in(1))/lon_inc) endif e_ind(i,j) = w_ind(i,j) + 1 js = ny_in*.5 do while (yG(i,j,bi,bj) .lt. y_in(js)) js = (js - 1)*.5 enddo do while (yG(i,j,bi,bj) .ge. y_in(js+1)) js = js + 1 enddo s_ind(i,j) = js n_ind(i,j) = js + 1 enddo enddo if (method .eq. 1) then C bilinear interpolation sp = 2 do j=1,sny do i=1,snx arrayout(i,j,bi,bj) = 0. do l=0,1 px_ind(l+1) = x_in(w_ind(i,j)+l) py_ind(l+1) = y_in(s_ind(i,j)+l) enddo do k=1,2 ew_val(k) = arrayin(w_ind(i,j),s_ind(i,j)+k-1) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j),s_ind(i,j)+k-1) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) arrayout(i,j,bi,bj)=arrayout(i,j,bi,bj) & +ew_val(k)*lagran(k,yG(i,j,bi,bj),py_ind,sp) enddo enddo enddo elseif (method .eq. 2) then C bicubic interpolation sp = 4 do j=1,sny do i=1,snx arrayout(i,j,bi,bj) = 0. do l=-1,2 px_ind(l+2) = x_in(w_ind(i,j)+l) py_ind(l+2) = y_in(s_ind(i,j)+l) enddo do k=1,4 ew_val(k) = & arrayin(w_ind(i,j)-1,s_ind(i,j)+k-2) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(w_ind(i,j) ,s_ind(i,j)+k-2) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j) ,s_ind(i,j)+k-2) & *lagran(3,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j)+1,s_ind(i,j)+k-2) & *lagran(4,xG(i,j,bi,bj),px_ind,sp) arrayout(i,j,bi,bj)=arrayout(i,j,bi,bj) & +ew_val(k)*lagran(k,yG(i,j,bi,bj),py_ind,sp) enddo enddo enddo else stop 'stop in exf_interp.F: interpolation method not supported' endif enddo enddo END