diff options
author | schnetter <> | 2004-05-07 20:06:00 +0000 |
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committer | schnetter <> | 2004-05-07 20:06:00 +0000 |
commit | 3eb21cd459e1a45da07365ddc016e8eacf9a3ed0 (patch) | |
tree | 6220e934561dc45daf6a17d4f6b5b6bda4f343ad /CarpetExtra/WaveToyFO/src/calcrhs.F77 | |
parent | 9c2a4d40a97be73549fe03b1b69687f775102dd5 (diff) |
Use first order instead of second order one-sided derivatives
darcs-hash:20040507200608-07bb3-14423f809f51630dfb7df946fe6a7e68e535e23a.gz
Diffstat (limited to 'CarpetExtra/WaveToyFO/src/calcrhs.F77')
-rw-r--r-- | CarpetExtra/WaveToyFO/src/calcrhs.F77 | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/CarpetExtra/WaveToyFO/src/calcrhs.F77 b/CarpetExtra/WaveToyFO/src/calcrhs.F77 index 8817d0701..c141654a0 100644 --- a/CarpetExtra/WaveToyFO/src/calcrhs.F77 +++ b/CarpetExtra/WaveToyFO/src/calcrhs.F77 @@ -1,4 +1,4 @@ -c $Header: /home/eschnett/C/carpet/Carpet/CarpetExtra/WaveToyFO/src/calcrhs.F77,v 1.6 2004/05/06 16:35:56 schnetter Exp $ +c $Header: /home/eschnett/C/carpet/Carpet/CarpetExtra/WaveToyFO/src/calcrhs.F77,v 1.7 2004/05/07 22:06:08 schnetter Exp $ #include "cctk.h" #include "cctk_Arguments.h" @@ -17,11 +17,14 @@ c $Header: /home/eschnett/C/carpet/Carpet/CarpetExtra/WaveToyFO/src/calcrhs. if (dir .eq. 0) then WaveToyFO_Deriv = (fp1 - fm1) / (2 * dx) else if (dir .eq. -1) then -c$$$ WaveToyFO_Deriv = (f0 - fm1) / dx - WaveToyFO_Deriv = (+ 3*f0 - 4*fm1 + fm2) / (2*dx) +c Use first order one-sided derivatives here. +c These are less dissipative than second order one-sided derivatives. +c (Sic.) + WaveToyFO_Deriv = (f0 - fm1) / dx +c$$$ WaveToyFO_Deriv = (+ 3*f0 - 4*fm1 + fm2) / (2*dx) else if (dir .eq. +1) then -c$$$ WaveToyFO_Deriv = (fp1 - f0) / dx - WaveToyFO_Deriv = (- 3*f0 + 4*fp1 - fp2) / (2*dx) + WaveToyFO_Deriv = (fp1 - f0) / dx +c$$$ WaveToyFO_Deriv = (- 3*f0 + 4*fp1 - fp2) / (2*dx) else call CCTK_WARN (0, "internal error") end if |