Scroll to navigation

dlasq5.f(3) LAPACK dlasq5.f(3)

NAME

dlasq5.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.
Wed Oct 15 2014 Version 3.4.2