get_ellipsoid_gate.m

一个目标跟踪系统的MATLAB 源程序包

% function [X, Y] = get_ellipsoid_gate(center, covariance, g)
%
% get the ellipsoid gate around the center
% useful for two dimensional plot of the estimated/predicted position
%
% center --- two dimensional position
% covariance --- two dimensional covariance matrix
% g --- size of the gate, default g=2
% X --- position of ellipsoid gate along X-axis
% Y --- position of ellipsoid gate along Y-axis

% by Huimin Chen, 09/10/01
function [X, Y] = get_ellipsoid_gate(center, covariance, g)
if nargin < 3
    g=2;
end

[V, D] = eig(covariance);
d = diag(D);
theta = linspace(0.01,2*pi,100);
d1 = [d(1).*cos(theta); d(2).*sin(theta)];
d2 = V * d1;
X = d2(1,:)+center(1);
Y = d2(2,:)+center(2);