DLASQ5(3)      LAPACK routine of NEC Numeric Library Collection      DLASQ5(3)



NAME
       DLASQ5

SYNOPSIS
       SUBROUTINE DLASQ5 (I0, N0, Z, PP, TAU, SIGMA, DMIN, DMIN1, DMIN2, DN,
           DNM1, DNM2, IEEE, EPS)



PURPOSE
            DLASQ5 computes one dqds transform in ping-pong form, one
            version for IEEE machines another for non IEEE machines.




ARGUMENTS
           I0        (input)
                     I0 is INTEGER
                   First index.

           N0        (input)
                     N0 is INTEGER
                   Last index.

           Z         (input)
                     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        (input)
                     PP is INTEGER
                   PP=0 for ping, PP=1 for pong.

           TAU       (input)
                     TAU is DOUBLE PRECISION
                   This is the shift.

           SIGMA     (input)
                     SIGMA is DOUBLE PRECISION
                   This is the accumulated shift up to this step.

           DMIN      (output)
                     DMIN is DOUBLE PRECISION
                   Minimum value of d.

           DMIN1     (output)
                     DMIN1 is DOUBLE PRECISION
                   Minimum value of d, excluding D( N0 ).

           DMIN2     (output)
                     DMIN2 is DOUBLE PRECISION
                   Minimum value of d, excluding D( N0 ) and D( N0-1 ).

           DN        (output)
                     DN is DOUBLE PRECISION
                   d(N0), the last value of d.

           DNM1      (output)
                     DNM1 is DOUBLE PRECISION
                   d(N0-1).

           DNM2      (output)
                     DNM2 is DOUBLE PRECISION
                   d(N0-2).

           IEEE      (input)
                     IEEE is LOGICAL
                   Flag for IEEE or non IEEE arithmetic.


           EPS       (input)
                     EPS is DOUBLE PRECISION
                   This is the value of epsilon used.



LAPACK routine                  31 October 2017                      DLASQ5(3)