.TH DGETRS 1 "November 2006" " LAPACK routine (version 3.1) " " LAPACK routine (version 3.1) "
.SH NAME
DGETRS - a system of linear equations A * X = B or A\(aq * X = B with a general N-by-N matrix A using the LU factorization computed by DGETRF
.SH SYNOPSIS
.TP 19
SUBROUTINE DGETRS(
TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
.TP 19
.ti +4
CHARACTER
TRANS
.TP 19
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INTEGER
INFO, LDA, LDB, N, NRHS
.TP 19
.ti +4
INTEGER
IPIV( * )
.TP 19
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DOUBLE
PRECISION A( LDA, * ), B( LDB, * )
.SH PURPOSE
DGETRS solves a system of linear equations
A * X = B or A\(aq * X = B
with a general N-by-N matrix A using the LU factorization computed
by DGETRF.
.SH ARGUMENTS
.TP 8
TRANS (input) CHARACTER*1
Specifies the form of the system of equations:
.br
= \(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
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
.TP 8
A (input) DOUBLE PRECISION array, dimension (LDA,N)
The factors L and U from the factorization A = P*L*U
as computed by DGETRF.
.TP 8
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
.TP 8
IPIV (input) INTEGER array, dimension (N)
The pivot indices from DGETRF; 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