Contents
dpotri - compute 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
SUBROUTINE DPOTRI(UPLO, N, A, LDA, INFO)
CHARACTER * 1 UPLO
INTEGER N, LDA, INFO
DOUBLE PRECISION A(LDA,*)
SUBROUTINE DPOTRI_64(UPLO, N, A, LDA, INFO)
CHARACTER * 1 UPLO
INTEGER*8 N, LDA, INFO
DOUBLE PRECISION A(LDA,*)
F95 INTERFACE
SUBROUTINE POTRI(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDA, INFO
REAL(8), DIMENSION(:,:) :: A
SUBROUTINE POTRI_64(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDA, INFO
REAL(8), DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void dpotri(char uplo, int n, double *a, int lda, int
*info);
void dpotri_64(char uplo, long n, double *a, long lda, long
*info);
dpotri 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.
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 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)
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 ille-
gal value
> 0: if INFO = i, the (i,i) element of the factor
U or L is zero, and the inverse could not be com-
puted.