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c/*@@
c @file AHFinder_mask.F
c @date November 1998
c @author Miguel Alcubierre
c @desc
c Set up horizon mask for black hole excision.
c @enddesc
c@@*/
c Note that including cactus.h will also include AHFinder.h
!#include "cactus.h"
#include "cctk.h"
#include "cctk_parameters.h"
#include "cctk_arguments.h"
subroutine AHFinder_mask(CCTK_FARGUMENTS)
! Set up the horizon mask. All this routine does is
! set up the value of the grid function "ahmask" to
! one for points outside the horizon, and to zero
! for points inside the horizon. This is only necessary
! if we want to use black hole excision.
use AHFinder_dat
implicit none
DECLARE_CCTK_FARGUMENTS
DECLARE_CCTK_PARAMETERS
integer i,j,k
CCTK_REAL zero,one
CCTK_REAL shrink
! *****************************
! *** DEFINE {zero,one} ***
! *****************************
zero = 0.0D0
one = 1.0D0
! *************************
! *** START ROUTINE ***
! *************************
call AHFinder_fun(CCTK_FARGUMENTS)
! Find out how big is the buffer zone. Notice that
! a negative value for shrink puts the masked region
! safely inside the horizon, while a positive value
! moves the masked region outside the horizon.
! shrink = getr8("ahf_maskshrink")*dx
shrink = ahf_maskshrink*dx
! Mask points.
do k=1,nz
do j=1,ny
do i=1,nx
if (ahfgrid(i,j,k).ge.shrink) then
ahmask(i,j,k) = one
else
ahmask(i,j,k) = zero
end if
end do
end do
end do
! ***************
! *** END ***
! ***************
end subroutine AHFinder_mask
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