.TH DGBTRS 1 "November 2006" " LAPACK routine (version 3.1) " " LAPACK routine (version 3.1) "
.SH NAME
DGBTRS - a system of linear equations A * X = B or A\(aq * X = B with a general band matrix A using the LU factorization computed by DGBTRF
.SH SYNOPSIS
.TP 19
SUBROUTINE DGBTRS(
TRANS, N, KL, KU, NRHS, AB, LDAB, IPIV, B, LDB,
INFO )
.TP 19
.ti +4
CHARACTER
TRANS
.TP 19
.ti +4
INTEGER
INFO, KL, KU, LDAB, LDB, N, NRHS
.TP 19
.ti +4
INTEGER
IPIV( * )
.TP 19
.ti +4
DOUBLE
PRECISION AB( LDAB, * ), B( LDB, * )
.SH PURPOSE
DGBTRS solves a system of linear equations
A * X = B or A\(aq * X = B
with a general band matrix A using the LU factorization computed
by DGBTRF.
.SH ARGUMENTS
.TP 8
TRANS (input) CHARACTER*1
Specifies the form of the system of equations.
= \(aqN\(aq: A * X = B (No transpose)
.br
= \(aqT\(aq: A\(aq* X = B (Transpose)
.br
= \(aqC\(aq: A\(aq* X = B (Conjugate transpose = Transpose)
.TP 8
N (input) INTEGER
The order of the matrix A. N >= 0.
.TP 8
KL (input) INTEGER
The number of subdiagonals within the band of A. KL >= 0.
.TP 8
KU (input) INTEGER
The number of superdiagonals within the band of A. KU >= 0.
.TP 8
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
.TP 8
AB (input) DOUBLE PRECISION array, dimension (LDAB,N)
Details of the LU factorization of the band matrix A, as
computed by DGBTRF. U is stored as an upper triangular band
matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and
the multipliers used during the factorization are stored in
rows KL+KU+2 to 2*KL+KU+1.
.TP 8
LDAB (input) INTEGER
The leading dimension of the array AB. LDAB >= 2*KL+KU+1.
.TP 8
IPIV (input) INTEGER array, dimension (N)
The pivot indices; for 1 <= i <= N, row i of the matrix was
interchanged with row IPIV(i).
.TP 8
B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
On entry, the right hand side matrix B.
On exit, the solution matrix X.
.TP 8
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
.TP 8
INFO (output) INTEGER
= 0: successful exit
.br
< 0: if INFO = -i, the i-th argument had an illegal value