# spotri.f man page

spotri.f —

## Synopsis

### Functions/Subroutines

subroutinespotri(UPLO, N, A, LDA, INFO)SPOTRI

## Function/Subroutine Documentation

### subroutine spotri (characterUPLO, integerN, real, dimension( lda, * )A, integerLDA, integerINFO)

**SPOTRI**

**Purpose:**

```
SPOTRI computes the inverse of a real symmetric positive definite
matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
computed by SPOTRF.
```

**Parameters:**

*UPLO*

```
UPLO is CHARACTER*1
= 'U': Upper triangle of A is stored;
= 'L': Lower triangle of A is stored.
```

*N*

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

*A*

```
A is REAL array, dimension (LDA,N)
On entry, the triangular factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T, as computed by
SPOTRF.
On exit, the upper or lower triangle of the (symmetric)
inverse of A, overwriting the input factor U or L.
```

*LDA*

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

*INFO*

```
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, the (i,i) element of the factor U or L is
zero, and the inverse could not be computed.
```

**Author:**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**

November 2011

Definition at line 96 of file spotri.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK