DGTSL(3)

SYNOPSIS
SUBROUTINE DGTSL (N, C, D, E, B, INFO)

NAME
dgtsl - Solve a tridiagonal linear system.

LIBRARY
SLATEC (LINPACK)

CATEGORY
D2A2A

TYPE
DOUBLE PRECISION (SGTSL-S, DGTSL-D, CGTSL-C)

KEYWORDS
LINEAR ALGEBRA, LINPACK, MATRIX, SOLVE, TRIDIAGONAL

AUTHOR
Dongarra, J., (ANL)

DESCRIPTION
DGTSL given a general tridiagonal matrix and a right hand side will find the solution. On Entry N INTEGER is the order of the tridiagonal matrix. C DOUBLE PRECISION(N) is the subdiagonal of the tridiagonal matrix. C(2) through C(N) should contain the subdiagonal. On output C is destroyed. D DOUBLE PRECISION(N) is the diagonal of the tridiagonal matrix. On output D is destroyed. E DOUBLE PRECISION(N) is the superdiagonal of the tridiagonal matrix. E(1) through E(N-1) should contain the superdiagonal. On output E is destroyed. B DOUBLE PRECISION(N) is the right hand side vector. On Return B is the solution vector. INFO INTEGER = 0 normal value. = K if the K-th element of the diagonal becomes exactly zero. The subroutine returns when this is detected.

REFERENCES
J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W. Stewart, LINPACK Users' Guide, SIAM, 1979.

ROUTINES CALLED
(NONE)

REVISION HISTORY (YYMMDD)
780814 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900326 Removed duplicate information from DESCRIPTION section. (WRB)
920501 Reformatted the REFERENCES section. (WRB)