python之MSE、MAE、RMSE的使用
阿新 • • 發佈:2020-02-24
我就廢話不多說啦,直接上程式碼吧!
target = [1.5,2.1,3.3,-4.7,-2.3,0.75] prediction = [0.5,1.5,-2.2,0.1,-0.5] error = [] for i in range(len(target)): error.append(target[i] - prediction[i]) print("Errors: ",error) print(error) squaredError = [] absError = [] for val in error: squaredError.append(val * val)#target-prediction之差平方 absError.append(abs(val))#誤差絕對值 print("Square Error: ",squaredError) print("Absolute Value of Error: ",absError) print("MSE = ",sum(squaredError) / len(squaredError))#均方誤差MSE from math import sqrt print("RMSE = ",sqrt(sum(squaredError) / len(squaredError)))#均方根誤差RMSE print("MAE = ",sum(absError) / len(absError))#平均絕對誤差MAE targetDeviation = [] targetMean = sum(target) / len(target)#target平均值 for val in target: targetDeviation.append((val - targetMean) * (val - targetMean)) print("Target Variance = ",sum(targetDeviation) / len(targetDeviation))#方差 print("Target Standard Deviation = ",sqrt(sum(targetDeviation) / len(targetDeviation)))#標準差
補充拓展:迴歸模型指標:MSE 、 RMSE、 MAE、R2
sklearn呼叫
# 測試集標籤預測 y_predict = lin_reg.predict(X_test) # 衡量線性迴歸的MSE 、 RMSE、 MAE、r2 from math import sqrt from sklearn.metrics import mean_absolute_error from sklearn.metrics import mean_squared_error from sklearn.metrics import r2_score print("mean_absolute_error:",mean_absolute_error(y_test,y_predict)) print("mean_squared_error:",mean_squared_error(y_test,y_predict)) print("rmse:",sqrt(mean_squared_error(y_test,y_predict))) print("r2 score:",r2_score(y_test,y_predict))
原生實現
# 測試集標籤預測 y_predict = lin_reg.predict(X_test) # 衡量線性迴歸的MSE 、 RMSE、 MAE mse = np.sum((y_test - y_predict) ** 2) / len(y_test) rmse = sqrt(mse) mae = np.sum(np.absolute(y_test - y_predict)) / len(y_test) r2 = 1-mse/ np.var(y_test) print("mse:",mse," rmse:",rmse," mae:",mae," r2:",r2)
相關公式
MSE
RMSE
MAE
R2
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