未获得测试数据的正确 R2 分数

如何解决未获得测试数据的正确 R2 分数

我应该为我的训练数据和测试数据获得 R2 分数。通过下面的代码，我得到了正确的训练数据的R2分数，但是测试数据的R2分数是错误的。希望有人能帮助我。

from sklearn.linear_model import LinearRegression
from sklearn.preprocessing import PolynomialFeatures
from sklearn.metrics.regression import r2_score

np.random.seed(0)
n = 15
x = np.linspace(0,10,n) + np.random.randn(n)/5
y = np.sin(x)+x/6 + np.random.randn(n)/10
x = x.reshape(-1,1)
    
X_train,X_test,y_train,y_test = train_test_split(x,y,random_state = 0)
    
y_train_pred = np.zeros(shape=(10,len(y_train)))
y_test_pred = np.zeros(shape=(10,len(y_test)))
r2_train = np.zeros(shape=(10,))
r2_test = np.zeros(shape=(10,))
        
for i,degree in enumerate([0,1,2,3,4,5,6,7,8,9]):
    poly = PolynomialFeatures(degree=degree)
    X_train_poly = poly.fit_transform(X_train)
    poly.fit(X_train,y_train)
             
    linreg = LinearRegression()
    linreg.fit(X_train_poly,y_train)
       
    y_train_pred[i] = linreg.predict(poly.fit_transform(X_train))
    r2_train[i] = r2_score(y_train,y_train_pred[i])

for j,degree1 in enumerate([0,9]):
    poly1 = PolynomialFeatures(degree=degree1)
    X_test_poly = poly1.fit_transform(X_test)
    poly1.fit(X_test,y_test)
             
    linreg = LinearRegression()
    linreg.fit(X_test_poly,y_test)
      
    y_test_pred[j] = linreg.predict(poly1.fit_transform(X_test))
    r2_test[j] = r2_score(y_test,y_test_pred[j])

我附上我当前的输出以供参考。