redhat man page for dlasq3

DLASQ3(l)								 )								 DLASQ3(l)

NAME
       DLASQ3 - check for deflation, computes a shift (TAU) and calls dqds

SYNOPSIS
       SUBROUTINE DLASQ3( I0, N0, Z, PP, DMIN, SIGMA, DESIG, QMAX, NFAIL, ITER, NDIV, IEEE )

	   LOGICAL	  IEEE

	   INTEGER	  I0, ITER, N0, NDIV, NFAIL, PP

	   DOUBLE	  PRECISION DESIG, DMIN, QMAX, SIGMA

	   DOUBLE	  PRECISION Z( * )

PURPOSE
       DLASQ3  checks  for deflation, computes a shift (TAU) and calls dqds. In case of failure it changes shifts, and tries again until output is
       positive.

ARGUMENTS
       I0     (input) INTEGER
	      First index.

       N0     (input) INTEGER
	      Last index.

       Z      (input) DOUBLE PRECISION array, dimension ( 4*N )
	      Z holds the qd array.

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

       DMIN   (output) DOUBLE PRECISION
	      Minimum value of d.

       SIGMA  (output) DOUBLE PRECISION
	      Sum of shifts used in current segment.

       DESIG  (input/output) DOUBLE PRECISION
	      Lower order part of SIGMA

       QMAX   (input) DOUBLE PRECISION
	      Maximum value of q.

       NFAIL  (output) INTEGER
	      Number of times shift was too big.

       ITER   (output) INTEGER
	      Number of iterations.

       NDIV   (output) INTEGER
	      Number of divisions.

       TTYPE  (output) INTEGER
	      Shift type.

       IEEE   (input) LOGICAL
	      Flag for IEEE or non IEEE arithmetic (passed to DLASQ5).

LAPACK version 3.0						   15 June 2000 							 DLASQ3(l)