Numpy MaskedArray.masked_equal()函数| Python
在许多情况下,数据集可能不完整或因存在无效数据而受到污染。例如,传感器可能无法记录数据,或记录无效值。 numpy.ma
模块通过引入掩码数组提供了一种解决此问题的便捷方法。掩码数组是可能缺少或无效条目的数组。
numpy.MaskedArray.masked_equal()
函数用于屏蔽等于给定值的数组。
Syntax : numpy.ma.masked_equal(arr, value, copy=True)
Parameters:
arr : [ndarray] Input array which we want to mask.
value : [int] Element of masked array which we want to mask.
copy : [bool] If True (default) make a copy of arr in the result. If False modify arr in place and return a view.
Return : [ MaskedArray] The result of masking.
代码#1:
# Python program explaining
# numpy.MaskedArray.masked_equal() method
# importing numpy as geek
# and numpy.ma module as ma
import numpy as geek
import numpy.ma as ma
# creating input array
in_arr = geek.array([1, 2, 3, -1, 2])
print ("Input array : ", in_arr)
# applying MaskedArray.masked_equal methods
# to input array where value = 2
mask_arr = ma.masked_equal(in_arr, 2)
print ("Masked array : ", mask_arr)
输出:
Input array : [ 1 2 3 -1 2]
Masked array : [1 -- 3 -1 --]
代码#2:
# Python program explaining
# numpy.MaskedArray.masked_equal() method
# importing numpy as geek
# and numpy.ma module as ma
import numpy as geek
import numpy.ma as ma
# creating input array
in_arr = geek.array([2e8, 3e-5, -45.0, 2e5, 5e2])
print ("Input array : ", in_arr)
# applying MaskedArray.masked_equal methods
# to input array where value = 5e2
mask_arr = ma.masked_equal(in_arr, 5e2)
print ("Masked array : ", mask_arr)
输出:
Input array : [ 2.0e+08 3.0e-05 -4.5e+01 2.0e+05 5.0e+02]
Masked array : [200000000.0 3e-05 -45.0 200000.0 --]