rain, <span class="string">'preproc'</span>, pp);
    ypredTrain = linregPredict(model, xtrain);
    ypredTest = linregPredict(model, xtest);
    mseTrain(m) = mean((ytrain-ypredTrain).^2);
    mseTest(m) = mean((ytest-ypredTest).^2);

    figure;
    plot(xtrain,ytrain,<span class="string">'.b'</span>, <span class="string">'markersize'</span>, 50);
    hold <span class="string">on</span>;
    plot(xtest, ypredTest, <span class="string">'k'</span>, <span class="string">'linewidth'</span>, 3, <span class="st