DLASQ6(1LAPACK routine (version 3.2)DLASQ6(1)NAME
DLASQ6 - computes one dqd (shift equal to zero) transform in ping-pong
form, with protection against underflow and overflow
SYNOPSIS
SUBROUTINE DLASQ6( I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2 )
INTEGER I0, N0, PP
DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DNM1, DNM2
DOUBLE PRECISION Z( * )
PURPOSE
DLASQ6 computes one dqd (shift equal to zero) transform in ping-pong
form, with protection against underflow and overflow.
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.
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).
LAPACK routine (version 3.2) November 2008 DLASQ6(1)
