centos man page for dsbgv

dsbgv.f(3)							      LAPACK								dsbgv.f(3)

NAME
       dsbgv.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dsbgv (JOBZ, UPLO, N, KA, KB, AB, LDAB, BB, LDBB, W, Z, LDZ, WORK, INFO)
	   DSBGST

Function/Subroutine Documentation
   subroutine dsbgv (characterJOBZ, characterUPLO, integerN, integerKA, integerKB, double precision, dimension( ldab, * )AB, integerLDAB, double
       precision, dimension( ldbb, * )BB, integerLDBB, double precision, dimension( * )W, double precision, dimension( ldz, * )Z, integerLDZ,
       double precision, dimension( * )WORK, integerINFO)
       DSBGST

       Purpose:

	    DSBGV computes all the eigenvalues, and optionally, the eigenvectors
	    of a real generalized symmetric-definite banded eigenproblem, of
	    the form A*x=(lambda)*B*x. Here A and B are assumed to be symmetric
	    and banded, and B is also positive definite.

       Parameters:
	   JOBZ

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

	   UPLO

		     UPLO is CHARACTER*1
		     = 'U':  Upper triangles of A and B are stored;
		     = 'L':  Lower triangles of A and B are stored.

	   N

		     N is INTEGER
		     The order of the matrices A and B.  N >= 0.

	   KA

		     KA is INTEGER
		     The number of superdiagonals of the matrix A if UPLO = 'U',
		     or the number of subdiagonals if UPLO = 'L'. KA >= 0.

	   KB

		     KB is INTEGER
		     The number of superdiagonals of the matrix B if UPLO = 'U',
		     or the number of subdiagonals if UPLO = 'L'. KB >= 0.

	   AB

		     AB is DOUBLE PRECISION array, dimension (LDAB, N)
		     On entry, the upper or lower triangle of the symmetric band
		     matrix A, stored in the first ka+1 rows of the array.  The
		     j-th column of A is stored in the j-th column of the array AB
		     as follows:
		     if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j;
		     if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka).

		     On exit, the contents of AB are destroyed.

	   LDAB

		     LDAB is INTEGER
		     The leading dimension of the array AB.  LDAB >= KA+1.

	   BB

		     BB is DOUBLE PRECISION array, dimension (LDBB, N)
		     On entry, the upper or lower triangle of the symmetric band
		     matrix B, stored in the first kb+1 rows of the array.  The
		     j-th column of B is stored in the j-th column of the array BB
		     as follows:
		     if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j;
		     if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb).

		     On exit, the factor S from the split Cholesky factorization
		     B = S**T*S, as returned by DPBSTF.

	   LDBB

		     LDBB is INTEGER
		     The leading dimension of the array BB.  LDBB >= KB+1.

	   W

		     W is DOUBLE PRECISION array, dimension (N)
		     If INFO = 0, the eigenvalues in ascending order.

	   Z

		     Z is DOUBLE PRECISION array, dimension (LDZ, N)
		     If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of
		     eigenvectors, with the i-th column of Z holding the
		     eigenvector associated with W(i). The eigenvectors are
		     normalized so that Z**T*B*Z = 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 >= N.

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (3*N)

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value
		     > 0:  if INFO = i, and i is:
			<= N:  the algorithm failed to converge:
			       i off-diagonal elements of an intermediate
			       tridiagonal form did not converge to zero;
			> N:   if INFO = N + i, for 1 <= i <= N, then DPBSTF
			       returned INFO = i: B is not positive definite.
			       The factorization of B could not be completed and
			       no eigenvalues or eigenvectors were computed.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 177 of file dsbgv.f.

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

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