pkg/generic_advdiff/gad_ppm_p3e_x.F

C $Header:  $
C $Name:  $

#     include "GAD_OPTIONS.h"

      SUBROUTINE GAD_PPM_P3E_X(bi,bj,kk,iy,
     &           mask,fbar,edge,myThid)
C     |================================================================|
C     | PPM_P3E_X: approximate edge values with degree-3 polynomials.  |
C     | Fixed grid-spacing variant in X.                               |
C     |================================================================|

          implicit none

C     =============================================== global variables
#         include "SIZE.h"
#         include "GRID.h"
#         include "GAD.h"

C     ====================================================== arguments
          integer bi,bj,kk,iy
          _RL mask(1-OLx:sNx+OLx)
          _RL fbar(1-OLx:sNx+OLx)
          _RL edge(1-OLx:sNx+OLx)
          integer myThid

C     ====================================================== variables
          integer ix
          _RL mloc(-2:+1)
          _RL floc(-2:+1)
          _RL ftmp

          do  ix = 1-OLx+2, sNx+OLx-1

C     ================ mask local stencil: expand from centre outwards
              mloc(-1) = mask(ix-1)
              mloc(+0) = mask(ix+0)

              floc(-1) = fbar(ix+0)
     &          + mloc(-1)*(fbar(ix-1)-fbar(ix+0))
              floc(+0) = fbar(ix-1)
     &          + mloc(+0)*(fbar(ix+0)-fbar(ix-1))

              mloc(-2) = mask(ix-2) * mloc(-1)

              ftmp = 2. _d 0 * floc(-1) - floc(+0)
              floc(-2) = ftmp
     &          + mloc(-2)*(fbar(ix-2)-ftmp)

              mloc(+1) = mask(ix+1) * mloc(+0)

              ftmp = 2. _d 0 * floc(+0) - floc(-1)
              floc(+1) = ftmp
     &          + mloc(+1)*(fbar(ix+1)-ftmp)

C     ================ centred, 3rd-order interpolation for edge value
              edge(ix) =
     &      -(1. _d 0 / 12. _d 0)*(floc(-2)+floc(+1))
     &      +(7. _d 0 / 12. _d 0)*(floc(-1)+floc(+0))

          end do

          return

c     end subroutine GAD_PPM_P3E_X
      end
1	jmc	1.1	C $Header: $
2			C $Name: $
3
4			# include "GAD_OPTIONS.h"
5
6			SUBROUTINE GAD_PPM_P3E_X(bi,bj,kk,iy,
7			& mask,fbar,edge,myThid)
8			C \|================================================================\|
9			C \| PPM_P3E_X: approximate edge values with degree-3 polynomials. \|
10			C \| Fixed grid-spacing variant in X. \|
11			C \|================================================================\|
12
13			implicit none
14
15			C =============================================== global variables
16			# include "SIZE.h"
17			# include "GRID.h"
18			# include "GAD.h"
19
20			C ====================================================== arguments
21			integer bi,bj,kk,iy
22			_RL mask(1-OLx:sNx+OLx)
23			_RL fbar(1-OLx:sNx+OLx)
24			_RL edge(1-OLx:sNx+OLx)
25			integer myThid
26
27			C ====================================================== variables
28			integer ix
29			_RL mloc(-2:+1)
30			_RL floc(-2:+1)
31			_RL ftmp
32
33			do ix = 1-OLx+2, sNx+OLx-1
34
35			C ================ mask local stencil: expand from centre outwards
36			mloc(-1) = mask(ix-1)
37			mloc(+0) = mask(ix+0)
38
39			floc(-1) = fbar(ix+0)
40			& + mloc(-1)*(fbar(ix-1)-fbar(ix+0))
41			floc(+0) = fbar(ix-1)
42			& + mloc(+0)*(fbar(ix+0)-fbar(ix-1))
43
44			mloc(-2) = mask(ix-2) * mloc(-1)
45
46			ftmp = 2. _d 0 * floc(-1) - floc(+0)
47			floc(-2) = ftmp
48			& + mloc(-2)*(fbar(ix-2)-ftmp)
49
50			mloc(+1) = mask(ix+1) * mloc(+0)
51
52			ftmp = 2. _d 0 * floc(+0) - floc(-1)
53			floc(+1) = ftmp
54			& + mloc(+1)*(fbar(ix+1)-ftmp)
55
56			C ================ centred, 3rd-order interpolation for edge value
57			edge(ix) =
58			& -(1. _d 0 / 12. _d 0)*(floc(-2)+floc(+1))
59			& +(7. _d 0 / 12. _d 0)*(floc(-1)+floc(+0))
60
61			end do
62
63			return
64
65			c end subroutine GAD_PPM_P3E_X
66			end