dlasq3.f(3)							      LAPACK							       dlasq3.f(3)

NAME

       dlasq3.f -

SYNOPSIS

   Functions/Subroutines
       subroutine dlasq3 (I0, N0, Z, PP, DMIN, SIGMA, DESIG, QMAX, NFAIL, ITER, NDIV, IEEE, TTYPE, DMIN1, DMIN2, DN, DN1, DN2, G, TAU)
	   DLASQ3 checks for deflation, computes a shift and calls dqds. Used by sbdsqr.

Function/Subroutine Documentation
   subroutine dlasq3 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, double precisionDMIN, double precisionSIGMA, double
       precisionDESIG, double precisionQMAX, integerNFAIL, integerITER, integerNDIV, logicalIEEE, integerTTYPE, double precisionDMIN1, double
       precisionDMIN2, double precisionDN, double precisionDN1, double precisionDN2, double precisionG, double precisionTAU)
       DLASQ3 checks for deflation, computes a shift and calls dqds. Used by sbdsqr.

       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.

       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.

	   PP

		     PP is INTEGER
		    PP=0 for ping, PP=1 for pong.
		    PP=2 indicates that flipping was applied to the Z array
		    and that the initial tests for deflation should not be
		    performed.

	   DMIN

		     DMIN is DOUBLE PRECISION
		    Minimum value of d.

	   SIGMA

		     SIGMA is DOUBLE PRECISION
		    Sum of shifts used in current segment.

	   DESIG

		     DESIG is DOUBLE PRECISION
		    Lower order part of SIGMA

	   QMAX

		     QMAX is DOUBLE PRECISION
		    Maximum value of q.

	   NFAIL

		     NFAIL is INTEGER
		    Number of times shift was too big.

	   ITER

		     ITER is INTEGER
		    Number of iterations.

	   NDIV

		     NDIV is INTEGER
		    Number of divisions.

	   IEEE

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

	   TTYPE

		     TTYPE is INTEGER
		    Shift type.

	   DMIN1

		     DMIN1 is DOUBLE PRECISION

	   DMIN2

		     DMIN2 is DOUBLE PRECISION

	   DN

		     DN is DOUBLE PRECISION

	   DN1

		     DN1 is DOUBLE PRECISION

	   DN2

		     DN2 is DOUBLE PRECISION

	   G

		     G is DOUBLE PRECISION

	   TAU

		     TAU is DOUBLE PRECISION

		    These are passed as arguments in order to save their values
		    between calls to DLASQ3.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Definition at line 181 of file dlasq3.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       dlasq3.f(3)