theta = [0:0.1:2 * pi];
%rand( 70, 1) * 2 * pi;

S2 = 0.25 * (rand( 30, 2 ) -0.5 );


S = 1 * [ cos(theta'), sin(theta') ];




S3 = [ S; S2 ];


[clusterLabels] = ngcluster( S3, 2, 0.3 );
