c-----------------------------------------------------------------------
c One-dimensional restriction operator for AMROC.
c A coarse cell value is overwritten by the mean value
c of all refined cells within this particular coarse cell.
c
c Interface:
c mfx := shape of fine grid
c mcx := shape of coarse grid
c
c uf() := fine grid
c uc() := coarse grid
c
c lbc(1) := lower bound for coarse grid
c ubc(1) := upper bound for coarse grid
c lbf(1) := lower bound for fine grid
c ubf(1) := upper bound for fine grid
c lbr(1) := lower bound for region restriction desired
c ufr(1) := upper bound for region restriction desired
c shaper(1) := shape of region restriction desired
c
c Copyright (C) 2002 Ralf Deiterding
c Brandenburgische Universitaet Cottbus
c
c Copyright (C) 2003-2007 California Institute of Technology
c Ralf Deiterding, ralf@amroc.net
c-----------------------------------------------------------------------
subroutine restrict1(uf,mfx,lbf,ubf,
& uc,mcx,lbc,ubc,
& lbr,ubr,shaper,meqn,mbc)
implicit none
integer meqn, mbc, mcx, mfx
integer shaper(1)
double precision uf(meqn,mfx), uc(meqn,mcx)
integer lbf(1), ubf(1),
& lbc(1), ubc(1),
& lbr(1), ubr(1)
c Local variables
integer i, ii, imin, imax, m, ifine, icoarse, refine,
& stridec, stridef, getindx, mbcf
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
c See definition of member-function extents() in BBox.h
c for calculation of stride
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
stridec = (ubc(1) - lbc(1))/(mcx-1)
stridef = (ubf(1) - lbf(1))/(mfx-1)
refine = stridec/stridef
mbcf = mbc * stridef
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
c Find coarse domain over which to refine
c Take three regions and select out intersection
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
imin = max(lbf(1)+mbcf, lbc(1), lbr(1))
imax = min(ubf(1)-mbcf, ubc(1), ubr(1))
if (mod(imin-lbc(1),stridec) .ne. 0) then
imin = imin + stridec - mod(imin-lbc(1),stridec)
endif
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
c Inject points to coarse grid from fine grid
c Loop from lower bound to upper bound with stride of refine.
c Convert the integer coordinates to fine and coarse grid absolute
c coordinates...
c- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
do 10 i = imin, imax, stridec
ifine = getindx(i, lbf(1), stridef)
icoarse = getindx(i, lbc(1), stridec)
! if (icoarse .gt. mcx ) then
! write(0,*)'ERROR in restriction: ',icoarse
! end if
do 10 m=1, meqn
uc(m,icoarse) = 0
do 20 ii = 0, refine-1
uc(m,icoarse) = uc(m,icoarse) + uf(m,ifine+ii)
20 continue
uc(m,icoarse) = uc(m,icoarse) / refine
10 continue
return
end