zpotf2.f man page

zpotf2.f —

Synopsis

Functions/Subroutines

subroutine zpotf2 (UPLO, N, A, LDA, INFO)
ZPOTF2 computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblocked algorithm).

Function/Subroutine Documentation

subroutine zpotf2 (characterUPLO, integerN, complex*16, dimension( lda, * )A, integerLDA, integerINFO)

ZPOTF2 computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblocked algorithm).

Purpose:

ZPOTF2 computes the Cholesky factorization of a complex Hermitian
positive definite matrix A.

The factorization has the form
   A = U**H * U ,  if UPLO = 'U', or
   A = L  * L**H,  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
Hermitian 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 COMPLEX*16 array, dimension (LDA,N)
On entry, the Hermitian 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**H *U  or A = L*L**H.

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 zpotf2.f.

Author

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Referenced By

zpotf2(3) is an alias of zpotf2.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK