回归评估指标

from sklearn.datasets import load_diabetes
from sklearn.neural_network import MLPRegressor
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.metrics import mean_squared_error, mean_absolute_error, r2_score
import numpy as np
diabetes = load_diabetes()
X_train, X_test, y_train, y_test = train_test_split(____)
scaler = StandardScaler()
X_train = scaler.fit_transform(____)
X_test = scaler.transform(____)
reg = MLPRegressor(hidden_layer_sizes=(____,), max_iter=____, random_state=____)
reg.fit(____)
y_pred = reg.predict(____)
mse = mean_squared_error(____)
rmse = np.sqrt(____)
mae = mean_absolute_error(____)
r2 = r2_score(____)
print(____)
print(____)
print(____)
print(____)