 'b:', 'linewidth', 3, 'displayname', 'truth');
plot(xtrain,ytrain, 'ro', 'markersize', 14, 'linewidth', 3, ...
    'displayname', 'training data');
NN = length(xtest);
ndx = 1:5:NN; % plot subset of errorbars to reduce clutter
sigma = sqrt(v);
h=legend('location', 'northwest');
set(h,'fontsize', fs); 
errorbar(xtest(ndx), mu(ndx), sigma(ndx));
title('Posterior predictive (known variance)', 'fontsize', fs);
printPmtkFigure('linregPostPredBayes')

%% Plot samples from posterior predictive
S = 10;
ws = gaussS