Python statistics harmonic_mean()用法及代码示例

谐波均值(也称为“相反均值”)是几种平均值之一，尤其是勾股均值之一。通常用于需要平均费率的情况。调和平均值也是给定一组观测值的倒数的算术平均值的倒数。

例如，harmonic mean 1、4和4的计算公式如下：

可以使用来自的harmonic_mean()函数将谐波均值合并到Python3中statistics模块。

用法： harmonic_mean([data-set])

参数：
[data-set]：是实数值的列表，元组或迭代器。

Returntype:返回给定数据集的harmonic_mean。

错误和异常：

StatisticsError当传递空的data-set时，或者data-set由负值组成时。
TypeError用于非数字类型值的数据集。

注意：仅使用列表，集合或任何序列中的正值来计算谐波均值。

代码1：

# Python3 code to demonstrate the  
# working of harmonic_mean() function 
  
# Import statistics module 
import statistics 
  
# list of positive real valued numbers 
data = [1, 3, 5, 7, 9] 
  
# using harmonic mean function to calculate 
# the harmonic mean of the given data-set 
print("Harmonic Mean is % s " % (statistics.harmonic_mean(data)))

输出：

Harmonic Mean is 2.797513321492007

代码2：

# Python3 program to demonstrate harmonic_mean() 
# function from the statistics module 
  
# Importing the statistics module 
from statistics import harmonic_mean 
  
# Importing fractions module as fr 
from fractions import Fraction as fr 
  
# tuple of positive integer numbers 
data1 = (2, 3, 4, 5, 7, 9, 11) 
  
# tuple of a set of floating point values 
data2 = (2.4, 5.1, 6.7, 8.9) 
  
# tuple of a set of fractional numbers 
data3 = (fr(1, 2), fr(44, 12), fr(10, 3), fr(2, 3)) 
  
# dictionary of a set of values 
# Only the keys are taken in 
# consideration by harmonic_mean() 
data4 = {1:"one", 2:"two", 3:"three"} 
  
# Printing the harmonic mean of above datsets 
print("Harmonic Mean of data set 1 is % s" 
                 % (harmonic_mean(data1))) 
                   
print("Harmonic Mean of data set 2 is % s" 
                 % (harmonic_mean(data2))) 
  
print("Harmonic Mean of data set 3 is % s" 
                 % (harmonic_mean(data3))) 
                   
print("Harmonic Mean of data set 4 is % s" 
                % (harmonic_mean(data4)))

输出：

Harmonic Mean of data set 1 is 4.299197943900386
Harmonic Mean of data set 2 is 4.574783168721765
Harmonic Mean of data set 4 is 55/56
Harmonic Mean of data set 5 is 1.6363636363636365

代码3：示范StatisticsError

# Python code to demonstrate StatisticsError 
# while using harmonic_mean() 
  
# importing statistics module 
import statistics 
  
# data-set of numbers containing 
# a negative number 
dat1 = [1, -1] 
  
# Statistics Error is raised when the 
# data-set passed as parameter is  
# empty or contain a negative value 
print(statistics.harmonic_mean(dat1))

输出：

Traceback (most recent call last):
  File "C:/Users/Souveek/PycharmProjects/Test.py", line 12, in 
    print(statistics.harmonic_mean((1, -1)))
  File "C:\Users\Souveek\AppData\Local\Programs\Python\Python36-32\Lib\statistics.py", line 356, in harmonic_mean
    T, total, count = _sum(1/x for x in _fail_neg(data, errmsg))
  File "C:\Users\Souveek\AppData\Local\Programs\Python\Python36-32\Lib\statistics.py", line 148, in _sum
    for n, d in map(_exact_ratio, values):
  File "C:\Users\Souveek\AppData\Local\Programs\Python\Python36-32\Lib\statistics.py", line 356, in 
    T, total, count = _sum(1/x for x in _fail_neg(data, errmsg))
  File "C:\Users\Souveek\AppData\Local\Programs\Python\Python36-32\Lib\statistics.py", line 285, in _fail_neg
    raise StatisticsError(errmsg)
statistics.StatisticsError:harmonic mean does not support negative values

注意：以下代码可能无法在在线IDE上运行，因为harmonic_mean()函数是Python3.6中新引入的

应用范围：
谐波均值是金融中许多重要工具(根据统计)。加权谐波平均值是平均乘数的优选方法，例如price-earnings比(P /E)，其中价格在分子内。它也用于算术平均值over-estimates为所需结果的地方的计算中。

相关用法

注：本文由纯净天空筛选整理自retr0大神的英文原创作品 Python statistics | harmonic_mean()。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。