dsterf(l) [redhat man page]

DSTERF(l)								 )								 DSTERF(l)

NAME

       DSTERF - compute all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm

SYNOPSIS

       SUBROUTINE DSTERF( N, D, E, INFO )

	   INTEGER	  INFO, N

	   DOUBLE	  PRECISION D( * ), E( * )

PURPOSE

       DSTERF computes all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm.

ARGUMENTS

       N       (input) INTEGER
	       The order of the matrix.  N >= 0.

       D       (input/output) DOUBLE PRECISION array, dimension (N)
	       On entry, the n diagonal elements of the tridiagonal matrix.  On exit, if INFO = 0, the eigenvalues in ascending order.

       E       (input/output) DOUBLE PRECISION array, dimension (N-1)
	       On entry, the (n-1) subdiagonal elements of the tridiagonal matrix.  On exit, E has been destroyed.

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value
	       > 0:  the algorithm failed to find all of the eigenvalues in a total of 30*N iterations; if INFO = i, then i elements of E have not
	       converged to zero.

LAPACK version 3.0						   15 June 2000 							 DSTERF(l)

dsterf.f(3)							      LAPACK							       dsterf.f(3)

NAME

       dsterf.f -

SYNOPSIS

   Functions/Subroutines
       subroutine dsterf (N, D, E, INFO)
	   DSTERF

Function/Subroutine Documentation
   subroutine dsterf (integerN, double precision, dimension( * )D, double precision, dimension( * )E, integerINFO)
       DSTERF

       Purpose:

	    DSTERF computes all eigenvalues of a symmetric tridiagonal matrix
	    using the Pal-Walker-Kahan variant of the QL or QR algorithm.

       Parameters:
	   N

		     N is INTEGER
		     The order of the matrix.  N >= 0.

	   D

		     D is DOUBLE PRECISION array, dimension (N)
		     On entry, the n diagonal elements of the tridiagonal matrix.
		     On exit, if INFO = 0, the eigenvalues in ascending order.

	   E

		     E is DOUBLE PRECISION array, dimension (N-1)
		     On entry, the (n-1) subdiagonal elements of the tridiagonal
		     matrix.
		     On exit, E has been destroyed.

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value
		     > 0:  the algorithm failed to find all of the eigenvalues in
			   a total of 30*N iterations; if INFO = i, then i
			   elements of E have not converged to zero.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 87 of file dsterf.f.

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

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