# zgetc2 (3) - Linux Manuals

zgetc2.f -

## SYNOPSIS

### Functions/Subroutines

subroutine zgetc2 (N, A, LDA, IPIV, JPIV, INFO)
ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

## Function/Subroutine Documentation

### subroutine zgetc2 (integerN, complex*16, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, integer, dimension( * )JPIV, integerINFO)

ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

``` ZGETC2 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*16 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 zgetc2.f.

## Author

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