cpptri()

subroutine cpptri	(	character	uplo,
		integer	n,
		complex, dimension( * )	ap,
		integer	info )

CPPTRI

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Purpose:

!>
!> CPPTRI computes the inverse of a complex Hermitian positive definite
!> matrix A using the Cholesky factorization A = U**H*U or A = L*L**H
!> computed by CPPTRF.
!> 

Parameters

[in]	UPLO	!> UPLO is CHARACTER*1 !> = 'U': Upper triangular factor is stored in AP; !> = 'L': Lower triangular factor is stored in AP. !>
[in]	N	!> N is INTEGER !> The order of the matrix A. N >= 0. !>
[in,out]	AP	!> AP is COMPLEX array, dimension (N*(N+1)/2) !> On entry, the triangular factor U or L from the Cholesky !> factorization A = U**H*U or A = L*L**H, packed columnwise as !> a linear array. The j-th column of U or L is stored in the !> array AP as follows: !> if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j; !> if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n. !> !> On exit, the upper or lower triangle of the (Hermitian) !> inverse of A, overwriting the input factor U or L. !>
[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.