#include <misc.h>
#include <params.h>
subroutine limdx(pidim ,ibeg ,len ,dx ,f ,& 1,5
fxl ,fxr )
!-----------------------------------------------------------------------
!
! Purpose:
! Limit the derivative estimates for data on an equally spaced grid
! so they satisfy the SCM0 condition, that is, the spline will be
! monotonic, but only C0 continuous on the domain
!
! Method:
!
! Author:
! Original version: J. Olson
! Standardized: J. Rosinski, June 1992
! Reviewed: D. Williamson, P. Rasch, August 1992
! Reviewed: D. Williamson, P. Rasch, March 1996
!
!-----------------------------------------------------------------------
!
! $Id: limdx.F90,v 1.1.44.2 2004/01/27 17:10:48 rosinski Exp $
! $Author: rosinski $
!
!-----------------------------------------------------------------------
use shr_kind_mod, only: r8 => shr_kind_r8
use pmgrid
use abortutils, only: endrun
!-----------------------------------------------------------------------
implicit none
!---------------------------Local parameters----------------------------
!
integer pbpts ! (length of latitude slice)*fields
parameter(pbpts = plond)
!
!------------------------------Arguments--------------------------------
!
! Input arguments
!
integer, intent(in) :: pidim ! vector dimension
integer, intent(in) :: ibeg ! index of vector to begin computation
integer, intent(in) :: len ! length of vector to compute
!
real(r8), intent(in) :: dx ! length of grid inteval
real(r8), intent(in) :: f(pidim) ! field
!
! Input/output arguments
!
real(r8), intent(inout) :: fxl(pidim) ! x-derivs at left edge of interval
real(r8), intent(inout) :: fxr(pidim) ! x-derivs at right edge of interval
!
!-----------------------------------------------------------------------
!
! pidim Length of f, fxl, and fxr.
! ibeg First interval of grid for which derivatives are computed.
! len Number of grid intervals for which derivatives are computed.
! (There are pidim - 1 intervals between the pidim gridpoints
! represented in f, fxl, and fxr.)
! dx Value of grid spacing.
! f Values on equally spaced grid from which derivatives fxl and
! fxr were computed.
! fxl fxl(i) is the limited derivative at the left edge of
! interval
! fxr fxr(i) is the limited derivative at the right edge of
! interval
!
!---------------------------Local variables-----------------------------
!
integer i ! index
integer iend ! index to end work on vector
!
real(r8) rdx ! 1./dx
real(r8) deli(pbpts) ! simple linear derivative
!
!-----------------------------------------------------------------------
!
if(pidim .gt. pbpts) then
write(6,9000) pidim
call endrun
end if
!
iend = ibeg + len - 1
rdx = 1./dx
!
do i = ibeg,iend
deli(i) = ( f(i+1) - f(i) )*rdx
end do
!
! Limiter
!
call scm0(len ,deli(ibeg),fxl(ibeg),fxr(ibeg))
!
return
9000 format('LIMDX: Local work array DELI not dimensioned large enough' &
,/' Increase local parameter pbpts to ',i5)
end subroutine limdx