tutorial 4

errors = zeros(num_folds, 1);
sizes = zeros(num_folds, 1);
for i = 1:num_folds
    classifier = learnGMMClassifier(folds{i}, folds_labels{i}, k);  % learn classifier on training data
    test_data = folds([1:(i-1) (i+1):num_folds]);
    test_data = vertcat(test_data{:});                              % prepare testing data
    test_labels = folds_labels([1:(i-1) (i+1):num_folds]);
    test_labels = vertcat(test_labels{:});                          % prepare testing labels
    predictions = classify(classifier, test_data);
    errors(i) = mean(predictions ~= test_labels);
    sizes(i) = size(folds{i}, 1);
end
e = mean((errors.*sizes)/mean(sizes));