---
name: "dgesc2"
section: "3lapack"
platform: "linux"
package: "liblapack-doc"
version: "3.2.1-8"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/dgesc2/3lapack"
---

# dgesc2(3lapack)

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

## NAME

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

## SYNOPSIS

- SUBROUTINE DGESC2(

  N, A, LDA, RHS, IPIV, JPIV, SCALE )

- INTEGER

  LDA, N

- DOUBLE

  PRECISION SCALE

- INTEGER

  IPIV( \* ), JPIV( \* )

- DOUBLE

  PRECISION A( LDA, \* ), RHS( \* )

## PURPOSE

DGESC2 solves a system of linear equations

## 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 (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) 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.\