NAME
DGESC2 - solve a system of linear equations A * X = scale* RHS with a general N-by-N matrix A using the LU factorization with complete pivoting computed by DGETC2
SYNOPSIS
SUBROUTINE DGESC2(
N, A, LDA, RHS, IPIV, JPIV, SCALE )
INTEGER
IPIV( * ), JPIV( * )
DOUBLE
PRECISION A( LDA, * ), RHS( * )
PURPOSE
DGESC2 solves a system of linear equations A * X = scale* RHS with a general N-by-N matrix A using the LU factorization with complete pivoting computed by DGETC2.
ARGUMENTS
N (input) INTEGER
The order of the matrix A.
A (input) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the LU part of the factorization of the n-by-n
matrix A computed by DGETC2: A = P * L * U * Q
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1, N).
RHS (input/output) DOUBLE PRECISION array, dimension (N).
On entry, the right hand side vector b.
On exit, the solution vector X.
IPIV (iput) INTEGER array, dimension (N).
The pivot indices; for 1 <= i <= N, row i of the
matrix has been interchanged with row IPIV(i).
JPIV (iput) INTEGER array, dimension (N).
The pivot indices; for 1 <= j <= N, column j of the
matrix has been interchanged with column JPIV(j).
SCALE (output) DOUBLE PRECISION
On exit, SCALE contains the scale factor. SCALE is chosen
0 <= SCALE <= 1 to prevent owerflow in the solution.
FURTHER DETAILS
Based on contributions by
Bo Kagstrom and Peter Poromaa, Department of Computing Science,
Umea University, S-901 87 Umea, Sweden.
ČLÁNKY DO MAILU