annotate toolboxes/FullBNT-1.0.7/KPMtools/draw_ellipse.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
rev   line source
wolffd@0 1 function h = draw_ellipse(x, c, outline_color, fill_color)
wolffd@0 2 % DRAW_ELLIPSE(x, c, outline_color, fill_color)
wolffd@0 3 % Draws ellipses at centers x with covariance matrix c.
wolffd@0 4 % x is a matrix of columns. c is a positive definite matrix.
wolffd@0 5 % outline_color and fill_color are optional.
wolffd@0 6
wolffd@0 7 n = 40; % resolution
wolffd@0 8 radians = [0:(2*pi)/(n-1):2*pi];
wolffd@0 9 unitC = [sin(radians); cos(radians)];
wolffd@0 10 r = chol(c)';
wolffd@0 11
wolffd@0 12 if nargin < 3
wolffd@0 13 outline_color = 'g';
wolffd@0 14 end
wolffd@0 15
wolffd@0 16 h = [];
wolffd@0 17 for i=1:cols(x)
wolffd@0 18 y = r*unitC + repmat(x(:, i), 1, n);
wolffd@0 19 if nargin < 4
wolffd@0 20 h = [h line(y(1,:), y(2,:), 'Color', outline_color)];
wolffd@0 21 else
wolffd@0 22 h = [h fill(y(1,:), y(2,:), fill_color, 'EdgeColor', outline_color)];
wolffd@0 23 end
wolffd@0 24 end