def run_PMF(X,M_training,M_test,K):
pmf = VariationalPMF(X,M_training,K)
pmf.initialize()
pmf.run(iterations,updates)
X_pred = pmf.predicted_X
# Calculate MSE of predictions.
MSE = statistics.MSE(X,X_pred,M_test)
print "Performance on test set: MSE=%s." % MSE
return MSE
