dpotri()

subroutine dpotri	(	character	uplo,
		integer	n,
		double precision, dimension( lda, * )	a,
		integer	lda,
		integer	info )

DPOTRI

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Purpose:

!>
!> 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 DPOTRF.
!> 

Parameters

[in]	UPLO	!> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !>
[in]	N	!> N is INTEGER !> The order of the matrix A. N >= 0. !>
[in,out]	A	!> A is DOUBLE PRECISION 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 !> DPOTRF. !> On exit, the upper or lower triangle of the (symmetric) !> inverse of A, overwriting the input factor U or L. !>
[in]	LDA	!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
[out]	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.