%GENCIRC Generation of a one-class circular dataset
%
% A = GENCIRC(N,S)
%
% INPUT
% N Size of dataset (optional; default: 50)
% S Standard deviation (optional; default: 0.1)
%
% OUTPUT
% A Dataset
%
% DESCRIPTION
% Generation of a uniformly distributed one-class 2D circular
% dataset with radius 1 superimposed with 1D normally distributed
% radial noise with standard deviation S. N points are generated.
% Defaults: N = 50, S = 0.1.
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, PRDATASETS
% Copyright: R.P.W. Duin, duin@ph.tn.tudelft.nl
% Faculty of Applied Sciences, Delft University of Technology
% P.O. Box 5046, 2600 GA Delft, The Netherlands
% $Id: gencirc.m,v 1.2 2006/03/08 22:06:58 duin Exp $
function a = gencirc(n,s)
if nargin < 1, n = 50; end
if nargin < 2, s = 0.1; end
if (length(s) > 1)
error('Standard deviation should be scalar')
end
alf = rand(n,1)*2*pi;
r = ones(n,1) + randn(n,1)*s;
a = [r.*sin(alf),r.*cos(alf)];
a = prdataset(a);
return;