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C $Header: /u/gcmpack/MITgcm/pkg/flt/flt_bilinear.F,v 1.4 2009/01/04 00:58:23 jmc Exp $ |
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C $Name: $ |
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|
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#include "FLT_OPTIONS.h" |
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|
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C-- Contents |
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C-- o FLT_BILINEAR |
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C-- o FLT_TRILINEAR |
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C-- o FLT_BILINEAR2D |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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|
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SUBROUTINE FLT_BILINEAR ( |
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I xp, |
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I yp, |
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O uu, |
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I kp, |
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I u, |
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I nu, |
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I bi, |
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I bj |
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& ) |
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|
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C ================================================================== |
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C SUBROUTINE flt_bilinear |
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C ================================================================== |
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C |
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C o Bilinear scheme to find u of particle at given xp,yp location |
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C |
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C ================================================================== |
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C SUBROUTINE flt_bilinear |
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C ================================================================== |
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|
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C == global variables == |
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|
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#include "SIZE.h" |
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|
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C == routine arguments == |
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|
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_RL xp, yp |
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_RL uu |
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INTEGER nu, kp, bi, bj |
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_RL u (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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|
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C == local variables == |
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|
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INTEGER nnx, nny, nfx, nfy, nfxp, nfyp |
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_RL dx, dy, ddx, ddy |
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_RL u11, u12, u22, u21 |
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|
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C == end of interface == |
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|
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IF ( kp.LT.1 .OR. kp.GT.Nr ) THEN |
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c WRITE(msgbuf,'(A,I8)') |
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c & ' FLT_BILINEAR: illegal value for kp=',kp |
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c CALL PRINT_ERROR( msgbuf, myThid ) |
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STOP 'ABNORMAL END: S/R FLT_BILINEAR' |
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ENDIF |
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nnx = int(xp) |
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nny = int(yp) |
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dx = xp - float(nnx) |
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dy = yp - float(nny) |
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|
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C to choose the u box in which the particle is found |
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C nu=1 for T, S |
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C nu=2 for u |
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C nu=3 for v |
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C nu=4 for w |
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|
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IF (nu.EQ.1.OR.nu.EQ.4) THEN |
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nfx = nnx |
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nfy = nny |
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ddx = dx |
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ddy = dy |
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ENDIF |
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|
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IF (nu.EQ.2) THEN |
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IF (dx.LE.0.5) THEN |
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nfx = nnx |
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ddx = dx + 0.5 |
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ELSE |
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nfx = nnx + 1 |
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ddx = dx - 0.5 |
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ENDIF |
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nfy = nny |
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ddy = dy |
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ENDIF |
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|
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IF (nu.EQ.3) THEN |
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IF (dy.LE.0.5) THEN |
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nfy = nny |
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ddy = dy + 0.5 |
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ELSE |
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nfy = nny + 1 |
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ddy = dy - 0.5 |
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ENDIF |
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nfx = nnx |
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ddx = dx |
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ENDIF |
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|
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Cab change start |
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C was correct only for global? |
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c IF (nfx.GT.nx) nfx=nfx-nx |
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IF (nfx.GT.nx) nfx=nx |
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Cab change end |
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IF (nfy.GT.ny) nfy=ny |
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nfxp = nfx + 1 |
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nfyp = nfy + 1 |
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Cab change start |
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c IF (nfx.EQ.nx) nfxp = 1 |
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IF (nfx.EQ.nx) nfxp = nfx |
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Cab change end |
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IF (nfy.EQ.ny) nfyp = nfy |
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|
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IF (nu.LT.4) THEN |
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u11 = u(nfx,nfy,kp,bi,bj) |
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u21 = u(nfxp,nfy,kp,bi,bj) |
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u22 = u(nfxp,nfyp,kp,bi,bj) |
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u12 = u(nfx,nfyp,kp,bi,bj) |
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ENDIF |
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IF (nu.EQ.4) THEN |
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Caw This may be incorrect. |
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u11 = u(nfx,nfy,kp,bi,bj)+u(nfx,nfy,kp-1,bi,bj) |
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u21 = u(nfxp,nfy,kp,bi,bj)+u(nfxp,nfy,kp-1,bi,bj) |
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u22 = u(nfxp,nfyp,kp,bi,bj)+u(nfxp,nfyp,kp-1,bi,bj) |
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u12 = u(nfx,nfyp,kp,bi,bj)+u(nfx,nfyp,kp-1,bi,bj) |
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ENDIF |
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|
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C bilinear interpolation (from numerical recipes) |
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uu = (1-ddx)*(1-ddy)*u11 + ddx*(1-ddy)*u21 + ddx*ddy*u22 |
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. + (1-ddx)*ddy*u12 |
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|
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RETURN |
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END |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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|
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SUBROUTINE FLT_TRILINEAR( |
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I xp, |
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I yp, |
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I zp, |
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O uu, |
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I u, |
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I nu, |
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I bi, |
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I bj |
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& ) |
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|
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C ================================================================== |
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C SUBROUTINE flt_trilinear |
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C ================================================================== |
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C |
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C o Trilinear scheme to find u of particle at a given xp,yp,zp |
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C location. This routine is a straight forward generalization of the |
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C bilinear interpolation scheme. |
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C |
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C started: 2004.05.28 Antti Westerlund (antti.westerlund@fimr.fi) |
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C and Sergio Jaramillo (sju@eos.ubc.ca). |
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C (adopted from SUBROUTINE bilinear by Arne Biastoch) |
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C |
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C ================================================================== |
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C SUBROUTINE flt_trilinear |
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C ================================================================== |
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|
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C == global variables == |
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|
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#include "SIZE.h" |
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|
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C == routine arguments == |
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|
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_RL xp, yp, zp |
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_RL uu |
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INTEGER nu, bi, bj |
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_RL u (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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|
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C == local variables == |
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|
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INTEGER nnx, nny, nnz, nfx, nfy, nfz, nfxp, nfyp, nfzp |
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_RL dx, dy, dz, ddx, ddy, ddz |
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_RL u111, u121, u221, u211, u112, u122, u222, u212 |
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|
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C == end of interface == |
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|
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C Round xp,yp,zp down to find a grid point. |
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nnx = int(xp) |
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nny = int(yp) |
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nnz = int(zp) |
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|
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C Find out the distance from the gridpoint. |
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dx = xp - float(nnx) |
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dy = yp - float(nny) |
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dz = zp - float(nnz) |
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|
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C to choose the u box in which the particle is found |
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C nu=1 for T, S |
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C nu=2 for u |
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C nu=3 for v |
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C nu=4 for w |
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|
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C Velocities are face quantities and must therefore be treated differently |
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|
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C If the variable is T,S |
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IF (nu.EQ.1) THEN |
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nfx = nnx |
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ddx = dx |
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nfy = nny |
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ddy = dy |
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nfz = nnz |
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ddz = dz |
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ENDIF |
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C If the variable is u |
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IF (nu.EQ.2) THEN |
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IF (dx.LE.0.5) THEN |
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nfx = nnx |
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ddx = dx + 0.5 |
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ELSE |
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nfx = nnx + 1 |
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ddx = dx - 0.5 |
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ENDIF |
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nfy = nny |
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ddy = dy |
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nfz = nnz |
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ddz = dz |
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ENDIF |
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C If the variable is v |
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IF (nu.EQ.3) THEN |
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nfx = nnx |
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ddx = dx |
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IF (dy.LE.0.5) THEN |
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nfy = nny |
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ddy = dy + 0.5 |
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ELSE |
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nfy = nny + 1 |
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ddy = dy - 0.5 |
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ENDIF |
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nfz = nnz |
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ddz = dz |
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ENDIF |
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C If the variable is w |
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IF (nu.EQ.4) THEN |
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nfx = nnx |
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ddx = dx |
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nfy = nny |
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ddy = dy |
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IF (dz.LE.0.5) THEN |
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nfz = nnz |
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ddz = dz + 0.5 |
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ELSE |
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nfz = nnz + 1 |
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ddz = dz - 0.5 |
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ENDIF |
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ENDIF |
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|
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C If we are near or over the edge, limit nfx/y/z |
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IF (nfx.GT.nx) nfx=nx |
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IF (nfy.GT.ny) nfy=ny |
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IF (nfz.GT.nr) nfz=nr |
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IF (nfz.LE.1) nfz=1 |
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C We should possibly check something else too... |
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|
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C the coordinates for the other grid points |
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nfxp = nfx + 1 |
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nfyp = nfy + 1 |
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nfzp = nfz + 1 |
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C If we are near the edge, also limit nf?p |
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IF (nfx.EQ.nx) nfxp = nfx |
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IF (nfy.EQ.ny) nfyp = nfy |
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IF (nfz.EQ.nr) nfzp = nfz |
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|
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C Values of the field at relevant grid points |
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u111 = u(nfx,nfy,nfz,bi,bj) |
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u211 = u(nfxp,nfy,nfz,bi,bj) |
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u221 = u(nfxp,nfyp,nfz,bi,bj) |
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u121 = u(nfx,nfyp,nfz,bi,bj) |
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u112 = u(nfx,nfy,nfzp,bi,bj) |
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u212 = u(nfxp,nfy,nfzp,bi,bj) |
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u222 = u(nfxp,nfyp,nfzp,bi,bj) |
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u122 = u(nfx,nfyp,nfzp,bi,bj) |
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|
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C Trilinear interpolation, a straight forward generalization |
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C of the bilinear interpolation scheme. |
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uu = (1-ddx)*(1-ddy)*(1-ddz)*u111 + ddx*(1-ddy)*(1-ddz)*u211 |
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& + ddx*ddy*(1-ddz)*u221 + (1-ddx)*ddy*(1-ddz)*u121 |
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& + (1-ddx)*(1-ddy)*ddz*u112 + ddx*(1-ddy)*ddz*u212 |
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& + ddx*ddy*ddz*u222 + (1-ddx)*ddy*ddz*u122 |
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|
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RETURN |
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END |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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|
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SUBROUTINE FLT_BILINEAR2D( |
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I xp, |
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I yp, |
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O uu, |
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I u, |
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I nu, |
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I bi, |
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I bj |
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& ) |
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|
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C ================================================================== |
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C SUBROUTINE flt_bilinear2d |
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C ================================================================== |
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C |
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C o Bilinear scheme to find u of particle at given xp,yp location |
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C o For 2D fields |
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C |
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C started: Arne Biastoch abiastoch@ucsd.edu 13-Jan-2000 |
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C (adopted from SUBROUTINE bilinear) |
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C |
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C ================================================================== |
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C SUBROUTINE flt_bilinear2d |
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C ================================================================== |
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|
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C == global variables == |
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|
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#include "SIZE.h" |
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|
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C == routine arguments == |
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|
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_RL xp, yp |
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_RL uu |
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INTEGER nu, bi, bj |
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_RL u (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
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|
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C == local variables == |
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|
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INTEGER nnx, nny, nfx, nfy, nfxp, nfyp |
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_RL dx, dy, ddx, ddy |
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_RL u11, u12, u22, u21 |
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|
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C == end of interface == |
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|
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nnx = int(xp) |
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nny = int(yp) |
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dx = xp - float(nnx) |
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dy = yp - float(nny) |
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|
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C to choose the u box in which the particle is found |
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C nu=1 for T, S |
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C nu=2 for u |
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C nu=3 for v |
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C nu=4 for w |
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|
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IF (nu.EQ.1.OR.nu.EQ.4) THEN |
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nfx = nnx |
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nfy = nny |
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ddx = dx |
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ddy = dy |
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ENDIF |
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|
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IF (nu.EQ.2) THEN |
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IF (dx.LE.0.5) THEN |
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nfx = nnx |
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ddx = dx + 0.5 |
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ELSE |
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nfx = nnx + 1 |
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ddx = dx - 0.5 |
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ENDIF |
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nfy = nny |
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ddy = dy |
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ENDIF |
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|
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IF (nu.EQ.3) THEN |
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IF (dy.LE.0.5) THEN |
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nfy = nny |
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ddy = dy + 0.5 |
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ELSE |
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nfy = nny + 1 |
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ddy = dy - 0.5 |
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ENDIF |
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nfx = nnx |
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ddx = dx |
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ENDIF |
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|
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Cab change start |
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C was correct only for global? |
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c IF (nfx.GT.nx) nfx=nfx-nx |
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IF (nfx.GT.nx) nfx=nx |
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Cab change end |
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IF (nfy.GT.ny) nfy=ny |
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nfxp = nfx + 1 |
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nfyp = nfy + 1 |
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Cab change start |
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c IF (nfx.EQ.nx) nfxp = 1 |
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IF (nfx.EQ.nx) nfxp = nfx |
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Cab change end |
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IF (nfy.EQ.ny) nfyp = nfy |
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|
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IF (nu.LT.4) THEN |
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u11 = u(nfx,nfy,bi,bj) |
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u21 = u(nfxp,nfy,bi,bj) |
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u22 = u(nfxp,nfyp,bi,bj) |
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u12 = u(nfx,nfyp,bi,bj) |
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ENDIF |
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IF (nu.EQ.4) THEN |
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Caw This may be incorrect. |
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u11 = u(nfx,nfy,bi,bj)+u(nfx,nfy,bi,bj) |
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u21 = u(nfxp,nfy,bi,bj)+u(nfxp,nfy,bi,bj) |
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u22 = u(nfxp,nfyp,bi,bj)+u(nfxp,nfyp,bi,bj) |
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u12 = u(nfx,nfyp,bi,bj)+u(nfx,nfyp,bi,bj) |
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ENDIF |
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|
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C bilinear interpolation (from numerical recipes) |
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uu = (1-ddx)*(1-ddy)*u11 + ddx*(1-ddy)*u21 + ddx*ddy*u22 |
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. + (1-ddx)*ddy*u12 |
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|
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RETURN |
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END |