Tridiagonal

INTERFACE:

   subroutine Tridiagonal (lbc, ubc, lbj, ubj, jtop, numf, filter, &
                           a, b, c, r, u)

DESCRIPTION:

Tridiagonal matrix solution

USES:

     use shr_kind_mod, only: r8 => shr_kind_r8

ARGUMENTS:

     implicit none
     integer , intent(in)    :: lbc, ubc               ! lbinning and ubing column indices
     integer , intent(in)    :: lbj, ubj               ! lbinning and ubing level indices
     integer , intent(in)    :: jtop(lbc:ubc)          ! top level for each column
     integer , intent(in)    :: numf                   ! filter dimension
     integer , intent(in)    :: filter(1:numf)         ! filter
     real(r8), intent(in)    :: a(lbc:ubc, lbj:ubj)    ! "a" left off diagonal of tridiagonal matrix
     real(r8), intent(in)    :: b(lbc:ubc, lbj:ubj)    ! "b" diagonal column for tridiagonal matrix
     real(r8), intent(in)    :: c(lbc:ubc, lbj:ubj)    ! "c" right off diagonal tridiagonal matrix
     real(r8), intent(in)    :: r(lbc:ubc, lbj:ubj)    ! "r" forcing term of tridiagonal matrix
     real(r8), intent(inout) :: u(lbc:ubc, lbj:ubj)    ! solution

CALLED FROM:

   subroutine BiogeophysicsLake in module BiogeophysicsLakeMod
   subroutine SoilTemperature in module SoilTemperatureMod
   subroutine SoilWater in module HydrologyMod

REVISION HISTORY:

   15 September 1999: Yongjiu Dai; Initial code
   15 December 1999:  Paul Houser and Jon Radakovich; F90 Revision
    1 July 2003: Mariana Vertenstein; modified for vectorization
   !OTHER LOCAL VARIABLES: