Simplified Gaussian elimination


INTERFACE:

   subroutine tridiagonal(N,fi,lt,value)
DESCRIPTION:

A linear equation with tridiagonal matrix structure is solved here. The main diagonal is stored on bu, the upper diagonal on au, and the lower diagonal on cu, the right hand side is stored on du. The method used here is the simplified Gauss elimination, also called Thomas algorithm.


USES:

   IMPLICIT NONE
INPUT PARAMETERS:
   integer, intent(in)                 :: N,fi,lt
OUTPUT PARAMETERS:
   REALTYPE                            :: value(0:N)
REVISION HISTORY:
   Original author(s): Hans Burchard & Karsten Bolding



Karsten Bolding 2012-12-28