slasq5.f(3)

Usage

Functions/Subroutines

subroutine slasq5 (i0, n0, z, pp, tau, sigma, dmin, dmin1, dmin2, dn, dnm1, dnm2, ieee, eps)
SLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr and sstegr.

Function/Subroutine Documentation

subroutine slasq5 (integer i0, integer n0, real, dimension( * ) z, integer pp, real tau, real sigma, real dmin, real dmin1, real dmin2, real dn, real dnm1, real dnm2, logical ieee, real eps)

SLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr and sstegr.

Purpose:

!>
!> SLASQ5 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 REAL 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 REAL
!>        This is the shift.
!>

SIGMA

!>          SIGMA is REAL
!>        This is the accumulated shift up to this step.
!>

DMIN

!>          DMIN is REAL
!>        Minimum value of d.
!>

DMIN1

!>          DMIN1 is REAL
!>        Minimum value of d, excluding D( N0 ).
!>

DMIN2

!>          DMIN2 is REAL
!>        Minimum value of d, excluding D( N0 ) and D( N0-1 ).
!>

DN

!>          DN is REAL
!>        d(N0), the last value of d.
!>

DNM1

!>          DNM1 is REAL
!>        d(N0-1).
!>

DNM2

!>          DNM2 is REAL
!>        d(N0-2).
!>

IEEE

!>          IEEE is LOGICAL
!>        Flag for IEEE or non IEEE arithmetic.
!>

EPS

!>         EPS is REAL
!>        This is the value of epsilon used.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 142 of file slasq5.f.

Releases

4 releases since Debian 7 (Wheezy); the text changed 3 times.

7
8
9
Arch