NAME¶

SLASQ5 - computes one dqds transform in ping-pong form, one version for IEEE machines another for non IEEE machines

SYNOPSIS¶

SUBROUTINE SLASQ5(

I0, N0, Z, PP, TAU, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, IEEE )

LOGICAL IEEE INTEGER I0, N0, PP REAL DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, TAU REAL Z( * )

PURPOSE¶

SLASQ5 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) REAL 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) REAL

This is the shift.

DMIN (output) REAL

Minimum value of d. DMIN1 (output) REAL Minimum value of d, excluding D( N0 ). DMIN2 (output) REAL Minimum value of d, excluding D( N0 ) and D( N0-1 ).

DN (output) REAL

d(N0), the last value of d.

DNM1 (output) REAL

d(N0-1).

DNM2 (output) REAL

d(N0-2).

IEEE (input) LOGICAL

Flag for IEEE or non IEEE arithmetic.