global data textdata numobs
global  x y j quadclass tree
global dtnum dtnode dtclass 
global  grpnum node grpname

tree = treefit(data(:,1:2), textdata);
[dtnum,dtnode,dtclass] = treeval(tree, data(:,1:2));
bad = ~strcmp(dtclass,textdata);
numobs = size(data,1);
sum(bad) / numobs
 
%% We use the same technique as above to visualize the regions assigned to each textdata.

[grpnum,node,grpname] = treeval(tree, [x y]);
gscatter(x,y,grpname,'grb','sod')
xlabel('Left-distance');
ylabel('Right-distance');
hold on;
plot(data(bad,1), data(bad,2), 'kx');
hold off;