目录
机器学习模型评估指标(回归)
1. 均方误差(Mean Squared Error, MSE)
2. 均方根误差(Root Mean Squared Error, RMSE)
3. 平均绝对误差(Mean Absolute Error, MAE)
4. 决定系数(Coefficient of Determination, R2)
import numpy as np
from sklearn.metrics import mean_squared_error
from sklearn.linear_model import LinearRegression
from sklearn.model_selection import train_test_split
from sklearn.datasets import make_regression
# 生成回归数据集
X, y = make_regression(n_samples=100, n_features=1, noise=0.5, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
# 训练线性回归模型
model = LinearRegression()
model.fit(X_train, y_train)
# 进行预测
y_pred = model.predict(X_test)
# 计算均方误差
mse = mean_squared_error(y_test, y_pred)
print(f"均方误差 (MSE): {mse}")
import numpy as np
from sklearn.metrics import mean_squared_error
from sklearn.linear_model import LinearRegression
from sklearn.model_selection import train_test_split
from sklearn.datasets import make_regression
# 生成回归数据集
X, y = make_regression(n_samples=100, n_features=1, noise=0.5, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
# 训练线性回归模型
model = LinearRegression()
model.fit(X_train, y_train)
# 进行预测
y_pred = model.predict(X_test)
# 计算均方根误差
rmse = np.sqrt(mean_squared_error(y_test, y_pred))
print(f"均方根误差 (RMSE): {rmse}")
import numpy as np
from sklearn.metrics import mean_absolute_error
from sklearn.linear_model import LinearRegression
from sklearn.model_selection import train_test_split
from sklearn.datasets import make_regression
# 生成回归数据集
X, y = make_regression(n_samples=100, n_features=1, noise=0.5, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
# 训练线性回归模型
model = LinearRegression()
model.fit(X_train, y_train)
# 进行预测
y_pred = model.predict(X_test)
# 计算平均绝对误差
mae = mean_absolute_error(y_test, y_pred)
print(f"平均绝对误差 (MAE): {mae}")
import numpy as np
from sklearn.metrics import r2_score
from sklearn.linear_model import LinearRegression
from sklearn.model_selection import train_test_split
from sklearn.datasets import make_regression
# 生成回归数据集
X, y = make_regression(n_samples=100, n_features=1, noise=0.5, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
# 训练线性回归模型
model = LinearRegression()
model.fit(X_train, y_train)
# 进行预测
y_pred = model.predict(X_test)
# 计算决定系数
r2 = r2_score(y_test, y_pred)
print(f"决定系数 (R^2): {r2}")
这些评估指标从不同的角度衡量了回归模型的性能,在实际应用中,我们通常会综合使用多个指标来全面评估模型的优劣。