# -*- coding: utf-8 -*- import math def get_average(records): """ 平均值 """ return sum(records) / len(records) def get_variance(records): """ 方差 反映一个数据集的离散程度 """ average = get_average(records) return sum([(x - average) ** 2 for x in records]) / len(records) def get_standard_deviation(records): """ 标准差 == 均方差 反映一个数据集的离散程度 """ variance = get_variance(records) return math.sqrt(variance) def get_rms(records): """ 均方根值 反映的是有效值而不是平均值 """ return math.sqrt(sum([x ** 2 for x in records]) / len(records)) def get_mse(records_real, records_predict): """ 均方误差 估计值与真值 偏差 """ if len(records_real) == len(records_predict): return sum([(x - y) ** 2 for x, y in zip(records_real, records_predict)]) / len(records_real) else: return None def get_rmse(records_real, records_predict): """ 均方根误差：是均方误差的算术平方根 """ mse = get_mse(records_real, records_predict) if mse: return math.sqrt(mse) else: return None def get_mae(records_real, records_predict): """ 平均绝对误差 """ if len(records_real) == len(records_predict): return sum([abs(x - y) for x, y in zip(records_real, records_predict)]) / len(records_real) else: return None if __name__ == '__main__': records1 = [3, 4, 5] records2 = [2, 4, 6] # 平均值 average1 = get_average(records1) # 4.0 average2 = get_average(records2) # 4.0 # 方差 variance1 = get_variance(records1) # 0.66 variance2 = get_variance(records2) # 2.66 # 标准差 std_deviation1 = get_standard_deviation(records1) # 0.81 std_deviation2 = get_standard_deviation(records2) # 1.63 # 均方根 rms1 = get_rms(records1) # 4.08 rms2 = get_rms(records2) # 4.32 # 均方误差 mse = get_mse(records1, records2) # 0.66 # 均方根误差 rmse = get_rmse(records1, records2) # 0.81 # 平均绝对误差 mae = get_mae(records1, records2) # 0.66
具体对某组数据操作可参考下例：
#导入math包import math#定义点的函数class Point: def __init__(self,x=0,y=0): self.x=x self.y=y def getx(self): return self.x def gety(self): return self.y #定义直线函数 class Getlen: def __init__(self,p1,p2): self.x=p1.getx()-p2.getx() self.y=p1.gety()-p2.gety() #用math.sqrt（）求平方根 self.len= math.sqrt((self.x**2)+(self.y**2)) #定义得到直线长度的函数 def getlen(self): return self.len #设置点p1的坐标为（0,0） p1=Point(0,0)#设置点p2的坐标为（3,4）p2=Point(3,4)#定义对象l=Getlen(p1,p2)#获取两点之间直线的长度d=l.getlen())
或者
import numpy as np import math p1=np.array([0,0]) p2=np.array([1000,2000]) p3=p2-p1 p4=math.hypot(p3[0],p3[1]) print(p4)