dlasq6.f man page

dlasq6.f —

Synopsis

Functions/Subroutines

subroutine dlasq6 (I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2)
DLASQ6 computes one dqd transform in ping-pong form. Used by sbdsqr and sstegr.

Function/Subroutine Documentation

subroutine dlasq6 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, double precisionDMIN, double precisionDMIN1, double precisionDMIN2, double precisionDN, double precisionDNM1, double precisionDNM2)

DLASQ6 computes one dqd transform in ping-pong form. Used by sbdsqr and sstegr.

Purpose:

DLASQ6 computes one dqd (shift equal to zero) transform in
ping-pong form, with protection against underflow and overflow.

Parameters:

I0

  I0 is INTEGER
First index.

N0

  N0 is INTEGER
Last index.

Z

  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

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

DMIN

  DMIN is DOUBLE PRECISION
Minimum value of d.

DMIN1

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

DMIN2

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

DN

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

DNM1

  DNM1 is DOUBLE PRECISION
d(N0-1).

DNM2

  DNM2 is DOUBLE PRECISION
d(N0-2).

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 119 of file dlasq6.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dlasq6(3) is an alias of dlasq6.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK