plot_partial_dependence.py 文件源码

def main():
    cal_housing = fetch_california_housing()

    # split 80/20 train-test
    X_train, X_test, y_train, y_test = train_test_split(cal_housing.data,
                                                        cal_housing.target,
                                                        test_size=0.2,
                                                        random_state=1)
    names = cal_housing.feature_names

    print("Training GBRT...", flush=True, end='')
    clf = GradientBoostingRegressor(n_estimators=100, max_depth=4,
                                    learning_rate=0.1, loss='huber',
                                    random_state=1)
    clf.fit(X_train, y_train)
    print(" done.")

    print('Convenience plot with ``partial_dependence_plots``')

    features = [0, 5, 1, 2, (5, 1)]
    fig, axs = plot_partial_dependence(clf, X_train, features,
                                       feature_names=names,
                                       n_jobs=3, grid_resolution=50)
    fig.suptitle('Partial dependence of house value on nonlocation features\n'
                 'for the California housing dataset')
    plt.subplots_adjust(top=0.9)  # tight_layout causes overlap with suptitle

    print('Custom 3d plot via ``partial_dependence``')
    fig = plt.figure()

    target_feature = (1, 5)
    pdp, axes = partial_dependence(clf, target_feature,
                                   X=X_train, grid_resolution=50)
    XX, YY = np.meshgrid(axes[0], axes[1])
    Z = pdp[0].reshape(list(map(np.size, axes))).T
    ax = Axes3D(fig)
    surf = ax.plot_surface(XX, YY, Z, rstride=1, cstride=1, cmap=plt.cm.BuPu)
    ax.set_xlabel(names[target_feature[0]])
    ax.set_ylabel(names[target_feature[1]])
    ax.set_zlabel('Partial dependence')
    #  pretty init view
    ax.view_init(elev=22, azim=122)
    plt.colorbar(surf)
    plt.suptitle('Partial dependence of house value on median age and '
                 'average occupancy')
    plt.subplots_adjust(top=0.9)

    plt.show()


# Needed on Windows because plot_partial_dependence uses multiprocessing