centos man page for slaqr1

slaqr1.f(3)							      LAPACK							       slaqr1.f(3)

NAME
       slaqr1.f -

SYNOPSIS
   Functions/Subroutines
       subroutine slaqr1 (N, H, LDH, SR1, SI1, SR2, SI2, V)
	   SLAQR1 sets a scalar multiple of the first column of the product of 2-by-2 or 3-by-3 matrix H and specified shifts.

Function/Subroutine Documentation
   subroutine slaqr1 (integerN, real, dimension( ldh, * )H, integerLDH, realSR1, realSI1, realSR2, realSI2, real, dimension( * )V)
       SLAQR1 sets a scalar multiple of the first column of the product of 2-by-2 or 3-by-3 matrix H and specified shifts.

       Purpose:

		 Given a 2-by-2 or 3-by-3 matrix H, SLAQR1 sets v to a
		 scalar multiple of the first column of the product

		 (*)  K = (H - (sr1 + i*si1)*I)*(H - (sr2 + i*si2)*I)

		 scaling to avoid overflows and most underflows. It
		 is assumed that either

			 1) sr1 = sr2 and si1 = -si2
		     or
			 2) si1 = si2 = 0.

		 This is useful for starting double implicit shift bulges
		 in the QR algorithm.

       Parameters:
	   N

		     N is integer
			 Order of the matrix H. N must be either 2 or 3.

	   H

		     H is REAL array of dimension (LDH,N)
			 The 2-by-2 or 3-by-3 matrix H in (*).

	   LDH

		     LDH is integer
			 The leading dimension of H as declared in
			 the calling procedure.  LDH.GE.N

	   SR1

		     SR1 is REAL

	   SI1

		     SI1 is REAL

	   SR2

		     SR2 is REAL

	   SI2

		     SI2 is REAL
			 The shifts in (*).

	   V

		     V is REAL array of dimension N
			 A scalar multiple of the first column of the
			 matrix K in (*).

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Contributors:
	   Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA

       Definition at line 122 of file slaqr1.f.

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

Version 3.4.2							  Tue Sep 25 2012						       slaqr1.f(3)