global data textdata x y j

load balance-scale

%% 作散點圖
 
gscatter(data(:,1), data(:,2),  textdata(:,1),'rgb','osd');
xlabel('Left-distance');
ylabel('Right-distance');
linclass = classify(data(:,1:2),data(:,1:2),textdata);
bad = ~strcmp(linclass,textdata);
numobs = size(data,1);
sum(bad) / numobs;
hold on;
plot(data(bad,1), data(bad,2), 'kx');
hold off;