Testing classification based on training size of 3000. We get a good
percentage correct by predicting everything is a non-whale! I am now
suspicious of the digit prediction. Really we ought to calculate the
ROC curve but it is not obvious how to do that from the code. I'd like
the AUC to be significanlty bigger for digits to convince myself it is
actually doing some reasonable classification. Also we are classifying
digits 0-9 but we only have samples which are 0 and 1 only! Changing
the target matrix gives a runtime error of some sort of
incompatibility of a 2 x 2 matrix and a 10 x matrix so somewhere in
the code is an assumption that the classifier is for digits 0-9 and is
not a general classifier. I think the best thing to do for now is use
scikit-learn with a neural net which also makes it easy to calculate
the ROC curve.