python之MSE、MAE、RMSE

target = [1.5, 2.1, 3.3, -4.7, -2.3, 0.75]  prediction = [0.5, 1.5, 2.1, -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))#误差绝对值      print("Square Error: ", squaredError)  print("Absolute Value of Error: ", absError)          print("MSE = ", sum(squaredError) / len(squaredError))#均方误差MSE          from math import sqrt  print("RMSE = ", sqrt(sum(squaredError) / len(squaredError)))#均方根误差RMSE  print("MAE = ", sum(absError) / len(absError))#平均绝对误差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)))#标准差