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dpotf2.f(3) LAPACK dpotf2.f(3)
NAME
dpotf2.f -
SYNOPSIS
Functions/Subroutines
subroutine dpotf2 (UPLO, N, A, LDA, INFO)
DPOTF2 computes the Cholesky factorization of a symmetric/Hermitian
positive definite matrix (unblocked algorithm).
Function/Subroutine Documentation
subroutine dpotf2 (characterUPLO, integerN, double precision, dimension(
lda, * )A, integerLDA, integerINFO)
DPOTF2 computes the Cholesky factorization of a symmetric/Hermitian
positive definite matrix (unblocked algorithm).
Purpose:
DPOTF2 computes the Cholesky factorization of a real symmetric
positive definite matrix A.
The factorization has the form
A = U**T * U , if UPLO = 'U', or
A = L * L**T, if UPLO = 'L',
where U is an upper triangular matrix and L is lower triangular.
This is the unblocked version of the algorithm, calling Level 2 BLAS.
Parameters:
UPLO
UPLO is CHARACTER*1
Specifies whether the upper or lower triangular part of the
symmetric matrix A is stored.
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the matrix A. N >= 0.
A
A is DOUBLE PRECISION array, dimension (LDA,N)
On entry, the symmetric matrix A. If UPLO = 'U', the leading
n by n upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = 'L', the
leading n by n lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit, if INFO = 0, the factor U or L from the Cholesky
factorization A = U**T *U or A = L*L**T.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
> 0: if INFO = k, the leading minor of order k is not
positive definite, and the factorization could not be
completed.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Definition at line 110 of file dpotf2.f.
Author
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Version 3.4.2 Sat Nov 16 2013 dpotf2.f(3)