dstev.f(3) [centos man page]

dstev.f(3)							      LAPACK								dstev.f(3)

NAME

       dstev.f -

SYNOPSIS

   Functions/Subroutines
       subroutine dstev (JOBZ, N, D, E, Z, LDZ, WORK, INFO)
	    DSTEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices

Function/Subroutine Documentation
   subroutine dstev (characterJOBZ, integerN, double precision, dimension( * )D, double precision, dimension( * )E, double precision, dimension(
       ldz, * )Z, integerLDZ, double precision, dimension( * )WORK, integerINFO)
	DSTEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices

       Purpose:

	    DSTEV computes all eigenvalues and, optionally, eigenvectors of a
	    real symmetric tridiagonal matrix A.

       Parameters:
	   JOBZ

		     JOBZ is CHARACTER*1
		     = 'N':  Compute eigenvalues only;
		     = 'V':  Compute eigenvalues and eigenvectors.

	   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
		     A.
		     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 A, stored in elements 1 to N-1 of E.
		     On exit, the contents of E are destroyed.

	   Z

		     Z is DOUBLE PRECISION array, dimension (LDZ, N)
		     If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal
		     eigenvectors of the matrix A, with the i-th column of Z
		     holding the eigenvector associated with D(i).
		     If JOBZ = 'N', then Z is not referenced.

	   LDZ

		     LDZ is INTEGER
		     The leading dimension of the array Z.  LDZ >= 1, and if
		     JOBZ = 'V', LDZ >= max(1,N).

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (max(1,2*N-2))
		     If JOBZ = 'N', WORK is not referenced.

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value
		     > 0:  if INFO = i, the algorithm failed to converge; i
			   off-diagonal elements of E did not converge to zero.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 117 of file dstev.f.

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

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

Check Out this Related Man Page

DSTEV(l)								 )								  DSTEV(l)

NAME

       DSTEV - compute all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix A

SYNOPSIS

       SUBROUTINE DSTEV( JOBZ, N, D, E, Z, LDZ, WORK, INFO )

	   CHARACTER	 JOBZ

	   INTEGER	 INFO, LDZ, N

	   DOUBLE	 PRECISION D( * ), E( * ), WORK( * ), Z( LDZ, * )

PURPOSE

       DSTEV computes all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix A.

ARGUMENTS

       JOBZ    (input) CHARACTER*1
	       = 'N':  Compute eigenvalues only;
	       = 'V':  Compute eigenvalues and eigenvectors.

       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 A.  On exit, if INFO = 0, the eigenvalues in ascending order.

       E       (input/output) DOUBLE PRECISION array, dimension (N)
	       On  entry,  the (n-1) subdiagonal elements of the tridiagonal matrix A, stored in elements 1 to N-1 of E; E(N) need not be set, but
	       is used by the routine.	On exit, the contents of E are destroyed.

       Z       (output) DOUBLE PRECISION array, dimension (LDZ, N)
	       If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal eigenvectors of the matrix A, with the i-th column  of  Z  holding  the
	       eigenvector associated with D(i).  If JOBZ = 'N', then Z is not referenced.

       LDZ     (input) INTEGER
	       The leading dimension of the array Z.  LDZ >= 1, and if JOBZ = 'V', LDZ >= max(1,N).

       WORK    (workspace) DOUBLE PRECISION array, dimension (max(1,2*N-2))
	       If JOBZ = 'N', WORK is not referenced.

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value
	       > 0:  if INFO = i, the algorithm failed to converge; i off-diagonal elements of E did not converge to zero.

LAPACK version 3.0						   15 June 2000 							  DSTEV(l)

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dstev.f(3) [centos man page]

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