dlasq5(3)

NAME

DLASQ5 - compute one dqds transform in ping-pong form, one

version for IEEE machines another for non IEEE machines

SYNOPSIS

SUBROUTINE DLASQ5( I0, N0, Z, PP, TAU, DMIN, DMIN1, DMIN2,
DN, DNM1, DNM2, IEEE )
    LOGICAL        IEEE
    INTEGER        I0, N0, PP
    DOUBLE         PRECISION DMIN, DMIN1, DMIN2, DN, DNM1,
DNM2, TAU
    DOUBLE         PRECISION Z( * )

PURPOSE

DLASQ5 computes one dqds transform in ping-pong form, one

version for IEEE machines another for non IEEE machines.

ARGUMENTS

I0 (input) INTEGER

First index.

N0 (input) INTEGER

Last index.

Z (input) DOUBLE PRECISION array, dimension ( 4*N )

Z holds the qd array. EMIN is stored in Z(4*N0) to

avoid an extra argument.

PP (input) INTEGER

PP=0 for ping, PP=1 for pong.

TAU (input) DOUBLE PRECISION

This is the shift.

DMIN (output) DOUBLE PRECISION

Minimum value of d.

DMIN1 (output) DOUBLE PRECISION Minimum value of d,

excluding D( N0 ).

DMIN2 (output) DOUBLE PRECISION Minimum value of d,

excluding D( N0 ) and D( N0-1 ).

DN (output) DOUBLE PRECISION

d(N0), the last value of d.

DNM1 (output) DOUBLE PRECISION

d(N0-1).

DNM2 (output) DOUBLE PRECISION

d(N0-2).

IEEE (input) LOGICAL

Flag for IEEE or non IEEE arithmetic.

LAPACK version 3.0 15 June 2000

DLASQ5(3)