diff options
| -rw-r--r-- | src/apply.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/src/apply.c b/src/apply.c index 353361f..160a691 100644 --- a/src/apply.c +++ b/src/apply.c @@ -514,6 +514,22 @@ BndReflectVI (cGH const * restrict const cctkGH, ioff[d] = 0; idir[d] = 1; } + /* To determine the correct expressions for ioff below, + * consider the definitions of iimin and iimax in the macro + * COPY_PRE above: + * + * iioff = ioff + (1 - idir) * imin + * iimin = iioff + idir * imin + * iimax = iioff + idir * imax + * + * We need idir = -1 since the loop copying into the + * symmetry zones traverses the grid points in opposite + * directions. + * + * Using the expressions above, one chooses the desired + * values of iimin and iimax, and can then solve the + * equations above for ioff. + */ if (face == 0) { imax[dir] = cctkGH->cctk_nghostzones[dir]; ioff[dir] = (+ 2*cctkGH->cctk_nghostzones[dir] - 1 @@ -521,8 +537,7 @@ BndReflectVI (cGH const * restrict const cctkGH, idir[dir] = -1; } else { imin[dir] = cctkGH->cctk_lsh[dir] - cctkGH->cctk_nghostzones[dir]; - ioff[dir] = (- 2*cctkGH->cctk_nghostzones[dir] + 1 - - (do_stagger[2*dir+face] ? 0 : 1)); + ioff[dir] = - 1 - (do_stagger[2*dir+face] ? 0 : 1); idir[dir] = -1; } |