def regression_cartree_modular(num_train=500,num_test=50,x_range=15,noise_var=0.2,ft=feattypes):
try:
from modshogun import RealFeatures, RegressionLabels, CSVFile, CARTree, PT_REGRESSION
from numpy import random
except ImportError:
print("Could not import Shogun and/or numpy modules")
return
random.seed(1)
# form training dataset : y=x with noise
X_train=random.rand(1,num_train)*x_range;
Y_train=X_train+random.randn(num_train)*noise_var
# form test dataset
X_test=array([[float(i)/num_test*x_range for i in range(num_test)]])
# wrap features and labels into Shogun objects
feats_train=RealFeatures(X_train)
feats_test=RealFeatures(X_test)
train_labels=RegressionLabels(Y_train[0])
# CART Tree formation
c=CARTree(ft,PT_REGRESSION,5,True)
c.set_labels(train_labels)
c.train(feats_train)
# Classify test data
output=c.apply_regression(feats_test).get_labels()
return c,output
