spotri(3P) Sun Performance Library spotri(3P)NAMEspotri - 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 * 1 UPLO
INTEGER N, LDA, INFO
REAL A(LDA,*)
SUBROUTINE SPOTRI_64(UPLO, N, A, LDA, INFO)
CHARACTER * 1 UPLO
INTEGER*8 N, LDA, INFO
REAL A(LDA,*)
F95 INTERFACE
SUBROUTINE POTRI(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A
SUBROUTINE POTRI_64(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void spotri(char uplo, int n, float *a, int lda, int *info);
void spotri_64(char uplo, long n, float *a, long lda, long *info);
PURPOSEspotri 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)
= 'U': Upper triangle of A is stored;
= 'L': Lower triangle of A is stored.
N (input) The order of the matrix A. N >= 0.
A (input/output)
On entry, the triangular factor U or L from the Cholesky fac‐
torization 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)
The leading dimension of the array A. LDA >= max(1,N).
INFO (output)
= 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.
6 Mar 2009 spotri(3P)
