cgetc2 (3) - Linux Man Pages

NAME

cgetc2.f -

SYNOPSIS


Functions/Subroutines


subroutine cgetc2 (N, A, LDA, IPIV, JPIV, INFO)
CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Function/Subroutine Documentation

subroutine cgetc2 (integerN, complex, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, integer, dimension( * )JPIV, integerINFO)

CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

 CGETC2 computes an LU factorization, using complete pivoting, of the
 n-by-n matrix A. The factorization has the form A = P * L * U * Q,
 where P and Q are permutation matrices, L is lower triangular with
 unit diagonal elements and U is upper triangular.

 This is a level 1 BLAS version of the algorithm.


 

Parameters:

N

          N is INTEGER
          The order of the matrix A. N >= 0.


A

          A is COMPLEX array, dimension (LDA, N)
          On entry, the n-by-n matrix to be factored.
          On exit, the factors L and U from the factorization
          A = P*L*U*Q; the unit diagonal elements of L are not stored.
          If U(k, k) appears to be less than SMIN, U(k, k) is given the
          value of SMIN, giving a nonsingular perturbed system.


LDA

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


IPIV

          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

          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).


INFO

          INFO is INTEGER
           = 0: successful exit
           > 0: if INFO = k, U(k, k) is likely to produce overflow if
                one tries to solve for x in Ax = b. So U is perturbed
                to avoid the overflow.


 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2013

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 112 of file cgetc2.f.

Author

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