zpotf2(3P) Sun Performance Library zpotf2(3P)NAMEzpotf2 - compute the Cholesky factorization of a complex Hermitian pos‐
itive definite matrix A
SYNOPSIS
SUBROUTINE ZPOTF2(UPLO, N, A, LDA, INFO)
CHARACTER * 1 UPLO
DOUBLE COMPLEX A(LDA,*)
INTEGER N, LDA, INFO
SUBROUTINE ZPOTF2_64(UPLO, N, A, LDA, INFO)
CHARACTER * 1 UPLO
DOUBLE COMPLEX A(LDA,*)
INTEGER*8 N, LDA, INFO
F95 INTERFACE
SUBROUTINE POTF2(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: N, LDA, INFO
SUBROUTINE POTF2_64(UPLO, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: N, LDA, INFO
C INTERFACE
#include <sunperf.h>
void zpotf2(char uplo, int n, doublecomplex *a, int lda, int *info);
void zpotf2_64(char uplo, long n, doublecomplex *a, long lda, long
*info);
PURPOSEzpotf2 computes the Cholesky factorization of a complex Hermitian posi‐
tive definite matrix A.
The factorization has the form
A = U' * U , if UPLO = 'U', or
A = L * L', 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.
ARGUMENTS
UPLO (input)
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored. = 'U': Upper triangular
= 'L': Lower triangular
N (input) The order of the matrix A. N >= 0.
A (input/output)
On entry, the Hermitian matrix A. If UPLO = 'U', the leading
n by n upper triangular part of A contains the upper triangu‐
lar 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'*U or A = L*L'.
LDA (input)
The leading dimension of the array A. LDA >= max(1,N).
INFO (output)
= 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 posi‐
tive definite, and the factorization could not be completed.
6 Mar 2009 zpotf2(3P)
