SGESC2(3)      LAPACK routine of NEC Numeric Library Collection      SGESC2(3)



NAME
       SGESC2

SYNOPSIS
       SUBROUTINE SGESC2 (N, A, LDA, RHS, IPIV, JPIV, SCALE)



PURPOSE
            SGESC2 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.




ARGUMENTS
           N         (input)
                     N is INTEGER
                     The order of the matrix A.

           A         (input)
                     A is 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)
                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1, N).

           RHS       (input/output)
                     RHS is REAL array, dimension (N).
                     On entry, the right hand side vector b.
                     On exit, the solution vector X.

           IPIV      (input)
                     IPIV is 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)
                     JPIV is 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)
                     SCALE is REAL
                      On exit, SCALE contains the scale factor. SCALE is chosen
                      0 <= SCALE <= 1 to prevent owerflow in the solution.



LAPACK routine                  31 October 2017                      SGESC2(3)