


CGESC2(3f)    LAPACK auxiliary routine (version 3.1)   CGESC2(3f)


NAME
       CGESC2 - a system of linear equations   A * X = scale* RHS  with a gen-
       eral N-by-N matrix A using the LU factorization with complete  pivoting
       computed by CGETC2

SYNOPSIS
       SUBROUTINE CGESC2( N, A, LDA, RHS, IPIV, JPIV, SCALE )

           INTEGER        LDA, N

           REAL           SCALE

           INTEGER        IPIV( * ), JPIV( * )

           COMPLEX        A( LDA, * ), RHS( * )

PURPOSE
       CGESC2 solves a system of linear equations



ARGUMENTS
       N       (input) INTEGER
               The number of columns of the matrix A.

       A       (input) COMPLEX array, dimension (LDA, N)
               On  entry,  the   LU  part  of  the factorization of the n-by-n
               matrix A computed by CGETC2:  A = P * L * U * Q

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

       RHS     (input/output) COMPLEX 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 November 2006                         1


