Machine Learning with Spark - Second Edition

L1 regularization

We can apply the same approach for differing levels of L1 regularization, as follows:

params = [0.0, 0.01, 0.1, 1.0, 10.0, 100.0, 1000.0] metrics = [evaluate(train_data, test_data, 10, 0.1, param, 'l1',    False) for param in params] print params print metrics plot(params, metrics) fig = matplotlib.pyplot.gcf() pyplot.xscale('log') 

Again, the results are more clearly seen when plotted in the following graph. We see that there is a much more subtle decline in RMSLE, and it takes a very high value to cause a jump back up. Here, the level of L1 regularization required is much higher than that for the L2 form; however, the overall performance is poorer:

[0.0, 0.01, 0.1, 1.0, 10.0, 100.0, 1000.0][1.5384660954019971, 1.5384518080419873, ...