table of contents
zlasyf_aa.f(3) | LAPACK | zlasyf_aa.f(3) |
NAME¶
zlasyf_aa.f
SYNOPSIS¶
Functions/Subroutines¶
subroutine zlasyf_aa (UPLO, J1, M, NB, A, LDA, IPIV,
H, LDH, WORK)
ZLASYF_AA
Function/Subroutine Documentation¶
subroutine zlasyf_aa (character UPLO, integer J1, integer M, integer NB, complex*16, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IPIV, complex*16, dimension( ldh, * ) H, integer LDH, complex*16, dimension( * ) WORK)¶
ZLASYF_AA
Purpose:
DLATRF_AA factorizes a panel of a complex symmetric matrix A using
the Aasen's algorithm. The panel consists of a set of NB rows of A
when UPLO is U, or a set of NB columns when UPLO is L.
In order to factorize the panel, the Aasen's algorithm requires the
last row, or column, of the previous panel. The first row, or column,
of A is set to be the first row, or column, of an identity matrix,
which is used to factorize the first panel.
The resulting J-th row of U, or J-th column of L, is stored in the
(J-1)-th row, or column, of A (without the unit diagonals), while
the diagonal and subdiagonal of A are overwritten by those of T.
Parameters:
UPLO
UPLO is CHARACTER*1
= 'U': Upper triangle of A is stored;
= 'L': Lower triangle of A is stored.
J1
J1 is INTEGER
The location of the first row, or column, of the panel
within the submatrix of A, passed to this routine, e.g.,
when called by ZSYTRF_AA, for the first panel, J1 is 1,
while for the remaining panels, J1 is 2.
M
M is INTEGER
The dimension of the submatrix. M >= 0.
NB
NB is INTEGER
The dimension of the panel to be facotorized.
A
A is COMPLEX*16 array, dimension (LDA,M) for
the first panel, while dimension (LDA,M+1) for the
remaining panels.
On entry, A contains the last row, or column, of
the previous panel, and the trailing submatrix of A
to be factorized, except for the first panel, only
the panel is passed.
On exit, the leading panel is factorized.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,M).
IPIV
IPIV is INTEGER array, dimension (M)
Details of the row and column interchanges,
the row and column k were interchanged with the row and
column IPIV(k).
H
H is COMPLEX*16 workspace, dimension (LDH,NB).
LDH
LDH is INTEGER
The leading dimension of the workspace H. LDH >= max(1,M).
WORK
WORK is COMPLEX*16 workspace, dimension (M).
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2017
Definition at line 146 of file zlasyf_aa.f.
Author¶
Generated automatically by Doxygen for LAPACK from the source code.
Tue Nov 14 2017 | Version 3.8.0 |