[p, q] = get_products();

% quantity sum over a day
%plot(sum(q'));

train_data = q( 1:28, :);
real_data  = q(29:42, :);

mean_data	= mean_pred(train_data, 14);
regress_data	= regress_pred(p, train_data);
quad_data	= quad_regress_pred(p, train_data);
log_data	= log_regress_pred(p, train_data);
sevenday_data	= repmat(sevenday_pred(train_data, 4), 2, 1);
random_data	= rand_pred(train_data, 14);

% plot prediction quallity
calc_error('mean',	real_data, mean_data);
calc_error('regress',	real_data, regress_data);
% quadratic just for reference, it sucks more than mean-predicition
calc_error('quad reg.',	real_data, quad_data);
calc_error('log reg.',	real_data, log_data);
calc_error('sevenday',	real_data, sevenday_data);
calc_error('random',	real_data, random_data);

[q2, removed] = remove_sevenday_frequency(q(1:14, :));
tmp = regress_pred(p([1:14 29:42],:), q2);
tmp = fft(tmp);
%tmp = (tmp .* (removed == 0)) + removed;
tmp = tmp + removed;
tmp = real(ifft(tmp));
calc_error('regress2', q(29:42, :), tmp);