dlasq5.f(3) LAPACK dlasq5.f(3)NAMEdlasq5.f-
SYNOPSIS
Functions/Subroutines
subroutine dlasq5 (I0, N0, Z, PP, TAU, SIGMA, DMIN, DMIN1, DMIN2, DN,
DNM1, DNM2, IEEE, EPS)
DLASQ5 computes one dqds transform in ping-pong form. Used by
sbdsqr and sstegr.
Function/Subroutine Documentation
subroutine dlasq5 (integerI0, integerN0, double precision, dimension( * )Z,
integerPP, double precisionTAU, double precisionSIGMA, double
precisionDMIN, double precisionDMIN1, double precisionDMIN2, double
precisionDN, double precisionDNM1, double precisionDNM2, logicalIEEE,
double precisionEPS)
DLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr
and sstegr.
Purpose:
DLASQ5 computes one dqds transform in ping-pong form, one
version for IEEE machines another for non IEEE machines.
Parameters:
I0
I0 is INTEGER
First index.
N0
N0 is INTEGER
Last index.
Z
Z is DOUBLE PRECISION array, dimension ( 4*N )
Z holds the qd array. EMIN is stored in Z(4*N0) to avoid
an extra argument.
PP
PP is INTEGER
PP=0 for ping, PP=1 for pong.
TAU
TAU is DOUBLE PRECISION
This is the shift.
SIGMA
SIGMA is DOUBLE PRECISION
This is the accumulated shift up to this step.
DMIN
DMIN is DOUBLE PRECISION
Minimum value of d.
DMIN1
DMIN1 is DOUBLE PRECISION
Minimum value of d, excluding D( N0 ).
DMIN2
DMIN2 is DOUBLE PRECISION
Minimum value of d, excluding D( N0 ) and D( N0-1 ).
DN
DN is DOUBLE PRECISION
d(N0), the last value of d.
DNM1
DNM1 is DOUBLE PRECISION
d(N0-1).
DNM2
DNM2 is DOUBLE PRECISION
d(N0-2).
IEEE
IEEE is LOGICAL
Flag for IEEE or non IEEE arithmetic.
EPS
EPS is DOUBLE PRECISION
This is the value of epsilon used.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Definition at line 144 of file dlasq5.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Sat Nov 16 2013 dlasq5.f(3)