Increase in R^2 as we increase n_estimators

bagged_trees_r2.py

import numpy as np
import matplotlib.pyplot as plt
from sklearn import metrics

preds = np.stack([t.predict(X_valid) for t in m.estimators_])
preds[:,0], np.mean(preds[:,0])
plt.plot([metrics.r2_score(y_valid, np.mean(preds[:i+1], axis=0)) for i in range(10)]);