# RedHat 9 (Linux i386) - man page for spotri (redhat section l)

```SPOTRI(l)								 )								 SPOTRI(l)

NAME
SPOTRI  - compute the inverse of a real symmetric positive definite matrix A using the Cholesky factorization A = U**T*U or A = L*L**T com-
puted by SPOTRF

SYNOPSIS
SUBROUTINE SPOTRI( UPLO, N, A, LDA, INFO )

CHARACTER	  UPLO

INTEGER	  INFO, LDA, N

REAL 	  A( LDA, * )

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  com-
puted by SPOTRF.

ARGUMENTS
UPLO    (input) CHARACTER*1
= 'U':  Upper triangle of A is stored;
= 'L':  Lower triangle of A is stored.

N       (input) INTEGER
The order of the matrix A.  N >= 0.

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

INFO    (output) 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.

LAPACK version 3.0						   15 June 2000 							 SPOTRI(l)```