ample(struct('mu', model.wN, 'Sigma', model.VN), S);
figure;
hold on;
plot(xtrain,ytrain, 'ro', 'markersize', 14, 'linewidth', 3, ...
    'displayname', 'training data');
for s=1:S
  tmp = modelMLE;  tmp.w = ws(s,:)';
  [mu] = linregPredict(tmp, Xtest);
  plot(xtest, mu, 'k-', 'linewidth', 2);
end
title('functions sampled from posterior', 'fontsize', fs)
printPmtkFigure('linregPostPredSamples')

%% Plot samples from  plug posterior predictive
S = 10;
figure;
hold on;
plot(xtrain,ytrain, 'ro', 'markersize', 