C $Header: /u/gcmpack/MITgcm/pkg/streamice/slope_limiter.F,v 1.2 2013/06/21 20:49:50 jmc Exp $ C $Name: $ #include "CPP_OPTIONS.h" ! _RL FUNCTION SLOPE_LIMITER (num, denom) _RL FUNCTION SLOPE_LIMITER (Cr) ! _RL num, denom ! _RL SLOPE_LIMITER ! _RL r _RL Cr ! used for flux limiting in advective subroutines ! Van Leer limiter (source: Wikipedia!) ! if (denom .eq. 0.0) then ! SLOPE_LIMITER = 0.0 ! elseif (num*denom .le. 0.0) then ! SLOPE_LIMITER = 0.0 ! else ! r = num/denom ! SLOPE_LIMITER = (r+abs(r))/(1+abs(r)) ! endif SLOPE_LIMITER = max(0.D0,max(min(1.D0,2.D0*Cr), & min(2.D0,Cr))) RETURN END