# cgetc2.f - Man Page

SRC/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 (integer n, complex, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

**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.

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

Definition at line **110** of file **cgetc2.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page cgetc2(3) is an alias of cgetc2.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK