spotri (l)  Linux Man Pages
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
Command to display spotri
manual in Linux: $ man l spotri
NAME
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
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
computed by SPOTRF.
ARGUMENTS
 UPLO (input) CHARACTER*1

= aqUaq: Upper triangle of A is stored;
= aqLaq: 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 ith 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.
Pages related to spotri
 spotri (3)
 spotrf (l)  computes the Cholesky factorization of a real symmetric positive definite matrix A
 spotrs (l)  solves a system of linear equations A*X = B with a symmetric positive definite matrix A using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPOTRF
 spotf2 (l)  computes the Cholesky factorization of a real symmetric positive definite matrix A
 spocon (l)  estimates the reciprocal of the condition number (in the 1norm) of a real symmetric positive definite matrix using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPOTRF
 spoequ (l)  computes row and column scalings intended to equilibrate a symmetric positive definite matrix A and reduce its condition number (with respect to the twonorm)
 spoequb (l)  computes row and column scalings intended to equilibrate a symmetric positive definite matrix A and reduce its condition number (with respect to the twonorm)
 sporfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is symmetric positive definite,