C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/exf/exf_interp.F,v 1.23 2008/01/24 08:29:51 mlosch Exp $ C $Name: $ #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 _RL FUNCTION LAGRAN(i,x,a,sp) INTEGER i _RS x _RL a(4) INTEGER sp C- local variables: INTEGER k _RL numer,denom numer = 1. _d 0 denom = 1. _d 0 #ifdef TARGET_NEC_SX !CDIR UNROLL=8 #endif /* TARGET_NEC_SX */ 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_in, yG, I lon_0, lon_inc, I lat_0, lat_inc, I nx_in, ny_in, method, mythid) implicit none C infile (string) :: name of the binary input file (direct access) C filePrec (integer) :: number of bits per word in file (32 or 64) C arrout ( _RL ) :: output array C irecord (integer) :: record number to read C xG,yG :: coordinates for output grid to interpolate to 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 (integer) :: size in x & y direction of input file to read C method :: 1,11,21 for bilinear; 2,12,22 for bicubic C :: 1,2 for tracer; 11,12 for U; 21,22 for V C myThid (integer) :: My Thread Id number 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 functions external lagran _RL lagran C local variables integer e_ind(snx,sny),w_ind(snx,sny) integer n_ind(snx,sny),s_ind(snx,sny) _RL px_ind(4), py_ind(4), ew_val(4) _RL arrayin(-1:nx_in+2 , -1:ny_in+2) _RL NorthValue _RL x_in (-1:nx_in+2), y_in(-1:ny_in+2) integer i, j, k, l, js, bi, bj, sp, interp_unit #ifdef TARGET_NEC_SX integer ic, ii, icnt integer inx(snx*sny,2) _RL ew_val1, ew_val2, ew_val3, ew_val4 #endif _RS xG(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) _RL ninety PARAMETER ( ninety = 90. ) _RS threeSixtyRS PARAMETER ( threeSixtyRS = 360. ) C put xG in interval [ lon_0 , lon_0+360 [ 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)-lon_0 & + threeSixtyRS*2. xG(i,j,bi,bj) = lon_0+mod(xG(i,j,bi,bj),threeSixtyRS) enddo enddo enddo enddo call exf_interp_read( I infile, filePrec, O arrayin, I irecord, nx_in, ny_in, mythid) C setup input longitude grid do i=-1,nx_in+2 x_in(i) = lon_0 + (i-1)*lon_inc enddo C setup input latitude grid 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 do j=ny_in+1,ny_in+2 if (y_in(j-1).eq.ninety) then y_in(j) = 2 * ninety - y_in(j-2) else y_in(j) = min( y_in(j-1)+lat_inc(ny_in-1), ninety ) endif enddo 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 For tracer (method=1,2) set to northernmost zonal-mean value C at 90N to avoid sharp zonal gradients near the Pole. C For U (method=11,12) set to zero at 90N to minimize velocity C gradient at North Pole C For V (method=11,12) set to northernmost zonal value at 90N, C as is already done above in order to allow cross-PoleArctic flow do j=ny_in,ny_in+2 if (y_in(j).eq.ninety) then if (method.eq.1 .or. method.eq.2) then NorthValue = 0. do i=1,nx_in NorthValue = NorthValue + arrayin(i,j) enddo NorthValue = NorthValue / nx_in do i=-1,nx_in+2 arrayin(i,j) = NorthValue enddo elseif (method.eq.11 .or. method.eq.12) then do i=-1,nx_in+2 arrayin(i,j) = 0. enddo endif endif enddo 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 enddo enddo #ifndef TARGET_NEC_SX C use the original and more readable variant of the algorithm that C has unvectorizable while-loops for each (i,j) do i=1,snx do j=1,sny 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 enddo enddo #else /* TARGET_NEC_SX defined */ C this variant vectorizes more efficiently than the original one because C it moves the while loops out of the i,j loops (loop pushing) but C it is ugly and incomprehensible icnt = 0 do j=1,sny do i=1,snx s_ind(i,j) = ny_in*.5 icnt = icnt+1 inx(icnt,1) = i inx(icnt,2) = j enddo enddo do while (icnt .gt. 0) ii = 0 !CDIR NODEP do ic=1,icnt i = inx(ic,1) j = inx(ic,2) if (yG(i,j,bi,bj) .lt. y_in(s_ind(i,j))) then s_ind(i,j) = (s_ind(i,j) - 1)*.5 ii = ii+1 inx(ii,1) = i inx(ii,2) = j endif enddo icnt = ii enddo icnt = 0 do j=1,sny do i=1,snx icnt = icnt+1 inx(icnt,1) = i inx(icnt,2) = j enddo enddo do while (icnt .gt. 0) ii = 0 !CDIR NODEP do ic=1,icnt i = inx(ic,1) j = inx(ic,2) if (yG(i,j,bi,bj) .ge. y_in(s_ind(i,j)+1)) then s_ind(i,j) = s_ind(i,j) + 1 ii = ii+1 inx(ii,1) = i inx(ii,2) = j endif enddo icnt = ii enddo #endif /* TARGET_NEC_SX defined */ do i=1,snx do j=1,sny n_ind(i,j) = s_ind(i,j) + 1 enddo enddo if (method.eq.1 .or. method.eq.11 .or. method.eq.21) 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 #ifndef TARGET_NEC_SX 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 #else ew_val1 = arrayin(w_ind(i,j),s_ind(i,j)+1-1) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j),s_ind(i,j)+1-1) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) ew_val2 = arrayin(w_ind(i,j),s_ind(i,j)+2-1) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j),s_ind(i,j)+2-1) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) arrayout(i,j,bi,bj)= & +ew_val1*lagran(1,yG(i,j,bi,bj),py_ind,sp) & +ew_val2*lagran(2,yG(i,j,bi,bj),py_ind,sp) #endif /* TARGET_NEC_SX defined */ enddo enddo elseif (method .eq. 2 .or. method.eq.12 .or. method.eq.22) 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 #ifndef TARGET_NEC_SX 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 #else ew_val1 = & arrayin(w_ind(i,j)-1,s_ind(i,j)+1-2) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(w_ind(i,j) ,s_ind(i,j)+1-2) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j) ,s_ind(i,j)+1-2) & *lagran(3,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j)+1,s_ind(i,j)+1-2) & *lagran(4,xG(i,j,bi,bj),px_ind,sp) ew_val2 = & arrayin(w_ind(i,j)-1,s_ind(i,j)+2-2) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(w_ind(i,j) ,s_ind(i,j)+2-2) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j) ,s_ind(i,j)+2-2) & *lagran(3,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j)+1,s_ind(i,j)+2-2) & *lagran(4,xG(i,j,bi,bj),px_ind,sp) ew_val3 = & arrayin(w_ind(i,j)-1,s_ind(i,j)+3-2) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(w_ind(i,j) ,s_ind(i,j)+3-2) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j) ,s_ind(i,j)+3-2) & *lagran(3,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j)+1,s_ind(i,j)+3-2) & *lagran(4,xG(i,j,bi,bj),px_ind,sp) ew_val4 = & arrayin(w_ind(i,j)-1,s_ind(i,j)+4-2) & *lagran(1,xG(i,j,bi,bj),px_ind,sp) & +arrayin(w_ind(i,j) ,s_ind(i,j)+4-2) & *lagran(2,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j) ,s_ind(i,j)+4-2) & *lagran(3,xG(i,j,bi,bj),px_ind,sp) & +arrayin(e_ind(i,j)+1,s_ind(i,j)+4-2) & *lagran(4,xG(i,j,bi,bj),px_ind,sp) arrayout(i,j,bi,bj)= & +ew_val1*lagran(1,yG(i,j,bi,bj),py_ind,sp) & +ew_val2*lagran(2,yG(i,j,bi,bj),py_ind,sp) & +ew_val3*lagran(3,yG(i,j,bi,bj),py_ind,sp) & +ew_val4*lagran(4,yG(i,j,bi,bj),py_ind,sp) #endif /* TARGET_NEC_SX defined */ enddo enddo else stop 'stop in exf_interp.F: interpolation method not supported' endif enddo enddo RETURN END