Matlab Cluster Ensemble Toolbox
28 Apr 2009
07 May 2009)
A Matlab toolbox for investigating the application of cluster ensembles to data classification.
function A = covm2d(theta,sx,sy)
%COVM2D 2-D covariance matrix.
% A = COVM2D(THETA,C) returns a 2-D covariance matrix given an angle,
% THETA, and scale factors, sx and sy. The columns of the orthogonal martix
% associated with the rotation by THETA represent the eigenvectors of the
% covariance matrix and the scale factors, sx and sy, represent the
% eigenvalues of the covariance matrix.
% Copyright (2009) Sandia Corporation. Under the terms of Contract
% DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
% certain rights in this software.
% orthognal rotation matrix (eigenvectr matrix)
Q = [cos(theta) -sin(theta); sin(theta) cos(theta)];
% covariance matrix
A = Q*[sx 0; 0 sy]*Q';