Provided by: liblapack-doc_3.3.1-1_all

**NAME**

LAPACK-3 - 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 SGETC2

**SYNOPSIS**

SUBROUTINE SGESC2( N, A, LDA, RHS, IPIV, JPIV, SCALE ) INTEGER LDA, N REAL SCALE INTEGER IPIV( * ), JPIV( * ) REAL A( LDA, * ), RHS( * )

**PURPOSE**

SGESC2 solves a system of linear equations

**ARGUMENTS**

N (input) INTEGER The order of the matrix A. A (input) REAL array, dimension (LDA,N) On entry, the LU part of the factorization of the n-by-n matrix A computed by SGETC2: A = P * L * U * Q LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1, N). RHS (input/output) REAL array, dimension (N). On entry, the right hand side vector b. On exit, the solution vector X. IPIV (input) INTEGER array, dimension (N). The pivot indices; for 1 <= i <= N, row i of the matrix has been interchanged with row IPIV(i). JPIV (input) 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) REAL 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. LAPACK auxiliary routine (version 3.2) April 2011 SGESC2(3lapack)