function [ classValue, errorRate ] = dtLearning(X, Y, category)
%dtLearning Builds decion trees on a subset, tets on the rest and
%returns the perfect errror. Repeats to get a value for all samples
%Category Selection:
%1 subtlety, 2 sphericity, 3 margin, 4 lobulation, 5 spiculation, 6 texture, 7 malignancy
Y = Y(:,category);
%Perform random sampling by just jumbling up the data then slicing the new
%set into 4ths or nths.
divisions = 10;
numSamples = size(X,1);
testSize = round(numSamples/divisions);
%get a random order of our rows
randomRows = randsample(numSamples, numSamples);
%get vector of row order to undo the scrambling of the rows
for i = 1:numSamples
restoreRows(i) = find(i == randomRows);
end
Xmixed = X(randomRows,:);
Ymixed = Y(randomRows,:);
%perform process repeatedly with the test set different each time untill
%all are covered.
classValue = 0;
testrows = cell(divisions,1);
for i = 1:(divisions - 1) %perform all iterations guaranteeed to have a full share
%start with testing at the beginning rows, then cycle down
testrows{i} = [(i-1)*testSize + 1:i*testSize];
Xtest = Xmixed(testrows{i}, :);
Ytest = Ymixed(testrows{i}, :);
Xtrain = Xmixed;
Xtrain(testrows{i},:) = [];
Ytrain = Ymixed;
Ytrain(testrows{i},:) = [];
tree = classregtree(Xtrain, Ytrain);
classValue = vertcat(classValue, eval(tree,Xtest));
end
%collect all the remaining rows. Could be undersized, but eliminates
%problems of some rows getting lost
testrows{divisions} = [(divisions-1)*testSize + 1:numSamples];
Xtest = Xmixed(testrows{divisions}, :);
Ytest = Ymixed(testrows{divisions}, :);
Xtrain = Xmixed;
Xtrain(testrows{divisions},:) = [];
Ytrain = Ymixed;
Ytrain(testrows{divisions},:) = [];
tree = classregtree(Xtrain, Ytrain);
classValue = vertcat(classValue(2:end,:), eval(tree,Xtest)); %Chop off the zero we put at the beginning
%Resort everything to the original order so we can compare against other
%algorithms
classValue = classValue(restoreRows,:);
%perform RMSE on allll the samples
errorRate = RMSE(classValue, Y); %RMSE error. Maybe better as an array so we can combine in the future
end