Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

CentOS 7.0 - man page for csteqr.f (centos section 3)

csteqr.f(3)				      LAPACK				      csteqr.f(3)

NAME
       csteqr.f -

SYNOPSIS
   Functions/Subroutines
       subroutine csteqr (COMPZ, N, D, E, Z, LDZ, WORK, INFO)
	   CSTEQR

Function/Subroutine Documentation
   subroutine csteqr (characterCOMPZ, integerN, real, dimension( * )D, real, dimension( * )E,
       complex, dimension( ldz, * )Z, integerLDZ, real, dimension( * )WORK, integerINFO)
       CSTEQR

       Purpose:

	    CSTEQR computes all eigenvalues and, optionally, eigenvectors of a
	    symmetric tridiagonal matrix using the implicit QL or QR method.
	    The eigenvectors of a full or band complex Hermitian matrix can also
	    be found if CHETRD or CHPTRD or CHBTRD has been used to reduce this
	    matrix to tridiagonal form.

       Parameters:
	   COMPZ

		     COMPZ is CHARACTER*1
		     = 'N':  Compute eigenvalues only.
		     = 'V':  Compute eigenvalues and eigenvectors of the original
			     Hermitian matrix.	On entry, Z must contain the
			     unitary matrix used to reduce the original matrix
			     to tridiagonal form.
		     = 'I':  Compute eigenvalues and eigenvectors of the
			     tridiagonal matrix.  Z is initialized to the identity
			     matrix.

	   N

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

	   D

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

	   E

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

	   Z

		     Z is COMPLEX array, dimension (LDZ, N)
		     On entry, if  COMPZ = 'V', then Z contains the unitary
		     matrix used in the reduction to tridiagonal form.
		     On exit, if INFO = 0, then if COMPZ = 'V', Z contains the
		     orthonormal eigenvectors of the original Hermitian matrix,
		     and if COMPZ = 'I', Z contains the orthonormal eigenvectors
		     of the symmetric tridiagonal matrix.
		     If COMPZ = 'N', then Z is not referenced.

	   LDZ

		     LDZ is INTEGER
		     The leading dimension of the array Z.  LDZ >= 1, and if
		     eigenvectors are desired, then  LDZ >= max(1,N).

	   WORK

		     WORK is REAL array, dimension (max(1,2*N-2))
		     If COMPZ = 'N', then WORK is not referenced.

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value
		     > 0:  the algorithm has failed to find all the eigenvalues in
			   a total of 30*N iterations; if INFO = i, then i
			   elements of E have not converged to zero; on exit, D
			   and E contain the elements of a symmetric tridiagonal
			   matrix which is unitarily similar to the original
			   matrix.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 133 of file csteqr.f.

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

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


All times are GMT -4. The time now is 12:37 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password