The first argument of tree_predictor.cpp is the test (prediction) data in the format same as training data, and the output 
is the accuray of the predictor on the test data.
For example, 
	./tree_predictor heart

Usage of the Makefile:
1. make tree : build the decision tree learner.
3. make run_tree FNAME=heart.train THETA=3: run the decision tree on data heart.train with theta = 3.
5. make predict_tree PNAME=heart.test :
   make prediction by the decision tree model on data heart.test .

You can play around with different FNAME, PNAME and THETA.