def _get_init_val(self, y):
return sum(y) / len(y)
2.4 计算残差
def _get_residuals(self, y, y_hat):..._get_init_val(y)
n = len(y)
y_hat = [self.init_val] * n
residuals = self....()
tree.fit(X_sub, residuals_sub, max_depth, min_samples_split)
self....,
res_hat_i in zip(y_hat, tree.predict(X))]
residuals = self...._get_residuals(y, y_hat)
self.trees.append(tree)
2.6 预测一个样本
def _predict(self, Xi):
return