Python Scipy stats.nanmean()用法及代码示例

scipy.stats.nanmean(array, axis=0)函数通过忽略沿数组指定轴的数组元素的Nan(不是数字)值来计算算术平均值。

它的公式-

参数：
array :输入具有包含Nan值的元素的数组或对象，以计算算术平均值。
axis : 要计算平均值的轴。默认情况下，轴= 0。

返回值：基于设置参数的数组元素的算术平均值(忽略Nan值)。

代码1：

# Arithmetic Mean  
import scipy 
import numpy as np 
  
arr1 = [1, 3, np.nan, 27]  
   
print("Arithmetic Mean using nanmean :", scipy.nanmean(arr1)) 
  
print("Arithmetic Mean without handling nan value :", scipy.mean(arr1))

输出：

Arithmetic Mean using nanmean : 10.333333333333334
Arithmetic Mean without handling nan value : nan

代码2：使用多维数据

# Arithmetic Mean  
from scipy import mean 
from scipy import nanmean 
import numpy as np 
  
arr1 = [[1, 3, 27],  
        [3, np.nan, 6],  
        [np.nan, 6, 3],  
        [3, 6, np.nan]]  
   
print("Arithmetic Mean is :", mean(arr1))  
print("Arithmetic Mean handling nan :", nanmean(arr1))  
  
# using axis = 0 
print("\nArithmetic Mean is with default axis = 0 : \n",  
      mean(arr1, axis = 0)) 
print("\nArithmetic Mean handling nan with default axis = 0 : \n",  
      nanmean(arr1, axis = 0)) 
  
# using axis = 1 
print("\nArithmetic Mean is with default axis = 1 : \n",  
      mean(arr1, axis = 1))   
print("\nArithmetic Mean handling nan with default axis = 1 : \n",  
      nanmean(arr1, axis = 1))

输出：

Arithmetic Mean is : nan
Arithmetic Mean handling nan : 6.444444444444445

Arithmetic Mean is with default axis =0 : 
 [nan nan nan]

Arithmetic Mean handling nan with default axis =0 : 
 [ 2.33333333  5.         12.        ]

Arithmetic Mean is with default axis =1 : 
 [10.33333333         nan         nan         nan]

Arithmetic Mean handling nan with default axis =1 : 
 [10.33333333  4.5         4.5         4.5       ]

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注：本文由纯净天空筛选整理自vishal3096大神的英文原创作品 sciPy stats.nanmean() function | Python。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。