# sgetrf.f man page

sgetrf.f —

## Synopsis

### Functions/Subroutines

subroutinesgetrf(M, N, A, LDA, IPIV, INFO)SGETRF

## Function/Subroutine Documentation

### subroutine sgetrf (integerM, integerN, real, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, integerINFO)

**SGETRF**

**Purpose:**

```
SGETRF computes an LU factorization of a general M-by-N matrix A
using partial pivoting with row interchanges.
The factorization has the form
A = P * L * U
where P is a permutation matrix, L is lower triangular with unit
diagonal elements (lower trapezoidal if m > n), and U is upper
triangular (upper trapezoidal if m < n).
This is the right-looking Level 3 BLAS version of the algorithm.
```

**Parameters:**

*M*

```
M is INTEGER
The number of rows of the matrix A. M >= 0.
```

*N*

```
N is INTEGER
The number of columns of the matrix A. N >= 0.
```

*A*

```
A is REAL array, dimension (LDA,N)
On entry, the M-by-N matrix to be factored.
On exit, the factors L and U from the factorization
A = P*L*U; the unit diagonal elements of L are not stored.
```

*LDA*

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

*IPIV*

```
IPIV is INTEGER array, dimension (min(M,N))
The pivot indices; for 1 <= i <= min(M,N), row i of the
matrix was interchanged with row IPIV(i).
```

*INFO*

```
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, U(i,i) is exactly zero. The factorization
has been completed, but the factor U is exactly
singular, and division by zero will occur if it is used
to solve a system of equations.
```

**Author:**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**

November 2011

Definition at line 109 of file sgetrf.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

sgetrf(3) is an alias of sgetrf.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK