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Diffstat (limited to 'Carpet/CarpetLib/src/prolongate_3d_cc_real8_tvd.F90')
| -rw-r--r-- | Carpet/CarpetLib/src/prolongate_3d_cc_real8_tvd.F90 | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/Carpet/CarpetLib/src/prolongate_3d_cc_real8_tvd.F90 b/Carpet/CarpetLib/src/prolongate_3d_cc_real8_tvd.F90 new file mode 100644 index 000000000..b39f43766 --- /dev/null +++ b/Carpet/CarpetLib/src/prolongate_3d_cc_real8_tvd.F90 @@ -0,0 +1,241 @@ +#include "cctk.h" + +! This routine performs "TVD" prolongation. It is intended to be used +! with GFs that are not expected to be smooth, particularly those +! that must also obey certain constraints. The obvious example is the +! density in hydrodynamics, which may be discontinuous yet must be +! strictly positive. +! +! To ensure that this prolongation method is used you should add the +! tag +! +! tags='Prolongation="TVD"' +! +! to the interface.ccl on the appropriate group. +! +! This applies minmod type limiting to the slope, checking over the +! entire coarse grid cell for the minimum modulus in each direction. + + + +! Grid point locations and their indices: +! +! global 0 4 12 20 28 | +! local | 0 1 2 3 | +! | C C C C | +! | f f f f f f f f | +! local | 0 1 2 3 4 5 6 7 | +! global 0 2 6 10 14 18 22 26 30 | +! +! Interpolation with even interpolation order: +! offset zero (fine index = 2 * coarse index): +! [1] +! offset one (fine index = 2 * coarse index + 1): +! [1] +! Interpolation with odd interpolation order: +! offset zero: +! [1 1 0]/2 +! offset one: +! [0 1 1]/2 +! The centres of these stencils are located at the coarse grid point +! corresponding to the fine grid point (the interpolation target) +! minus the offset. Example: fine grid 8 -> coarse grid 8, fine grid +! 12 -> also coarse grid 8. + + + +#define CHKIDX(i,j,k, imax,jmax,kmax, where) \ + if ((i)<1 .or. (i)>(imax) .or. (j)<1 .or. (j)>(jmax) .or. (k)<1 .or. (k)>(kmax)) then &&\ + write (msg, '(a, " array index out of bounds: shape is (",i4,",",i4,",",i4,"), index is (",i4,",",i4,",",i4,")")') (where), (imax),(jmax),(kmax), (i),(j),(k) &&\ + call CCTK_WARN (CCTK_WARN_ABORT, msg) &&\ + end if + + + +subroutine prolongate_3d_cc_real8_tvd (src, srciext, srcjext, & + srckext, dst, dstiext, dstjext, dstkext, srcbbox, & + dstbbox, regbbox) + + implicit none + + CCTK_REAL8, parameter :: one=1, fourth=one/4 + + integer srciext, srcjext, srckext + CCTK_REAL8 src(srciext,srcjext,srckext) + integer dstiext, dstjext, dstkext + CCTK_REAL8 dst(dstiext,dstjext,dstkext) + ! bbox(:,1) is lower boundary (inclusive) + ! bbox(:,2) is upper boundary (inclusive) + ! bbox(:,3) is stride + integer srcbbox(3,3), dstbbox(3,3), regbbox(3,3) + + character*1000 msg + + integer offsetlo, offsethi + + integer regiext, regjext, regkext + + integer dstifac, dstjfac, dstkfac + + integer srcioff, srcjoff, srckoff + integer dstioff, dstjoff, dstkoff + + integer i, j, k + integer i0, j0, k0 + integer fi, fj, fk + integer d + + CCTK_REAL8 :: dlo, dup + CCTK_REAL8 :: slopex, slopey, slopez + + do d=1,3 + if (srcbbox(d,3).eq.0 .or. dstbbox(d,3).eq.0 & + .or. regbbox(d,3).eq.0) then + call CCTK_WARN (0, "Internal error: stride is zero") + end if + if (srcbbox(d,3).le.regbbox(d,3) & + .or. dstbbox(d,3).ne.regbbox(d,3)) then + call CCTK_WARN (0, "Internal error: strides disagree") + end if + if (mod(srcbbox(d,3), dstbbox(d,3)).ne.0) then + call CCTK_WARN (0, "Internal error: destination strides are not integer multiples of the source strides") + end if +!!$ if (mod(srcbbox(d,1), srcbbox(d,3)).ne.0 & +!!$ .or. mod(dstbbox(d,1), dstbbox(d,3)).ne.0 & +!!$ .or. mod(regbbox(d,1), regbbox(d,3)).ne.0) then +!!$ call CCTK_WARN (0, "Internal error: array origins are not integer multiples of the strides") +!!$ end if + if (regbbox(d,1).gt.regbbox(d,2)) then + ! This could be handled, but is likely to point to an error elsewhere + call CCTK_WARN (0, "Internal error: region extent is empty") + end if + regkext = (regbbox(d,2) - regbbox(d,1)) / regbbox(d,3) + 1 + dstkfac = srcbbox(d,3) / dstbbox(d,3) + srckoff = (regbbox(d,1) - srcbbox(d,1)) / dstbbox(d,3) + offsetlo = regbbox(d,3) + if (mod(srckoff + 0, dstkfac).eq.0) then + offsetlo = 0 + if (regkext.gt.1) then + offsetlo = regbbox(d,3) + end if + end if + offsethi = regbbox(d,3) + if (mod(srckoff + regkext-1, dstkfac).eq.0) then + offsethi = 0 + if (regkext.gt.1) then + offsethi = regbbox(d,3) + end if + end if + if (regbbox(d,1)-offsetlo.lt.srcbbox(d,1) & + .or. regbbox(d,2)+offsethi.gt.srcbbox(d,2) & + .or. regbbox(d,1).lt.dstbbox(d,1) & + .or. regbbox(d,2).gt.dstbbox(d,2)) then + call CCTK_WARN (0, "Internal error: region extent is not contained in array extent") + end if + end do + + if (srciext.ne.(srcbbox(1,2)-srcbbox(1,1))/srcbbox(1,3)+1 & + .or. srcjext.ne.(srcbbox(2,2)-srcbbox(2,1))/srcbbox(2,3)+1 & + .or. srckext.ne.(srcbbox(3,2)-srcbbox(3,1))/srcbbox(3,3)+1 & + .or. dstiext.ne.(dstbbox(1,2)-dstbbox(1,1))/dstbbox(1,3)+1 & + .or. dstjext.ne.(dstbbox(2,2)-dstbbox(2,1))/dstbbox(2,3)+1 & + .or. dstkext.ne.(dstbbox(3,2)-dstbbox(3,1))/dstbbox(3,3)+1) then + call CCTK_WARN (0, "Internal error: array sizes don't agree with bounding boxes") + end if + + if (any(srcbbox(:,3) / dstbbox(:,3) /= 2)) then + call CCTK_WARN (0, "Internal error: refinement factor is not 2") + end if + + if (any(mod(regbbox(:,3), 2) /= 0)) then + call CCTK_WARN (0, "Internal error: region stride is not a multiple of 2") + end if + + regiext = (regbbox(1,2) - regbbox(1,1)) / regbbox(1,3) + 1 + regjext = (regbbox(2,2) - regbbox(2,1)) / regbbox(2,3) + 1 + regkext = (regbbox(3,2) - regbbox(3,1)) / regbbox(3,3) + 1 + + dstifac = 2 ! srcbbox(1,3) / dstbbox(1,3) + dstjfac = 2 ! srcbbox(2,3) / dstbbox(2,3) + dstkfac = 2 ! srcbbox(3,3) / dstbbox(3,3) + + srcioff = (regbbox(1,1) - srcbbox(1,1) + regbbox(1,3) / 2) / dstbbox(1,3) + srcjoff = (regbbox(2,1) - srcbbox(2,1) + regbbox(1,3) / 2) / dstbbox(2,3) + srckoff = (regbbox(3,1) - srcbbox(3,1) + regbbox(1,3) / 2) / dstbbox(3,3) + + dstioff = (regbbox(1,1) - dstbbox(1,1)) / dstbbox(1,3) + dstjoff = (regbbox(2,1) - dstbbox(2,1)) / dstbbox(2,3) + dstkoff = (regbbox(3,1) - dstbbox(3,1)) / dstbbox(3,3) + + if (srcioff<0 .or. srcjoff<0 .or. srckoff<0) then + call CCTK_WARN (0, "Internal error: source array offset is negative") + end if + + if (dstioff<0 .or. dstjoff<0 .or. dstkoff<0) then + call CCTK_WARN (0, "Internal error: destination array offset is negative") + end if + + ! Loop over fine region + + do k = 0, regkext-1 + k0 = (srckoff + k) / dstkfac + fk = mod(srckoff + k, dstkfac) + + do j = 0, regjext-1 + j0 = (srcjoff + j) / dstjfac + fj = mod(srcjoff + j, dstjfac) + + do i = 0, regiext-1 + i0 = (srcioff + i) / dstifac + fi = mod(srcioff + i, dstifac) + + ! We consider the nearest coarse grid point. From this + ! point, we use a slope to interpolate (or extrapolate, as + ! it may be) towards the interpolation point. We consider + ! both the left and the right slope starting from this + ! coarse grid point, and choose the minmod of these. This + ! is, loosely speaking, either the smaller of these slopes, + ! or zero if they differ too much. + + CHKIDX (i0 ,j0 ,k0 , srciext,srcjext,srckext, "src") + CHKIDX (i0+2,j0+2,k0+2, srciext,srcjext,srckext, "src") + + dlo = src(i0+1,j0+1,k0+1) - src(i0+0,j0+1,k0+1) + dup = src(i0+2,j0+1,k0+1) - src(i0+1,j0+1,k0+1) + slopex = (2*fi-1) * fourth * minmod(dlo,dup) + + dlo = src(i0+1,j0+1,k0+1) - src(i0+1,j0+0,k0+1) + dup = src(i0+1,j0+2,k0+1) - src(i0+1,j0+1,k0+1) + slopey = (2*fj-1) * fourth * minmod(dlo,dup) + + dlo = src(i0+1,j0+1,k0+1) - src(i0+1,j0+1,k0+0) + dup = src(i0+1,j0+1,k0+2) - src(i0+1,j0+1,k0+1) + slopez = (2*fk-1) * fourth * minmod(dlo,dup) + + CHKIDX (dstioff+i+1, dstjoff+j+1, dstkoff+k+1, dstiext,dstjext,dstkext, "dst") + + dst (dstioff+i+1, dstjoff+j+1, dstkoff+k+1) = & + src(i0+1,j0+1,k0+1) + slopex + slopey + slopez + + end do + end do + end do + +contains + + function minmod(a, b) + + CCTK_REAL8 minmod + CCTK_REAL8 a, b + + if (a * b < 0) then + minmod = 0 + else if (abs(a) < abs(b)) then + minmod = a + else + minmod = b + end if + + end function minmod + +end subroutine prolongate_3d_cc_real8_tvd |