Numpy MaskedArray.masked_less()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_less()
函数用于屏蔽小于给定值的数组。此函数是masked_where
的快捷方式, condition = (arr < value).
Syntax : numpy.ma.masked_less(arr, value, copy=True)
Parameters:
arr : [ndarray] Input array which we want to mask.
value : [int] It is used to mask the array element which are < value.
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 resultant array after masking.
代码#1:
# Python program explaining
# numpy.MaskedArray.masked_less() 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_less methods
# to input array where value<2
mask_arr = ma.masked_less(in_arr, 2)
print ("Masked array : ", mask_arr)
输出:
Input array : [ 1 2 3 -1 2]
Masked array : [-- 2 3 -- 2]
代码#2:
# Python program explaining
# numpy.MaskedArray.masked_less() 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([5e8, 3e-5, -45.0, 4e4, 5e2])
print ("Input array : ", in_arr)
# applying MaskedArray.masked_less methods
# to input array where value<5e2
mask_arr = ma.masked_less(in_arr, 5e2)
print ("Masked array : ", mask_arr)
输出:
Input array : [ 5.0e+08 3.0e-05 -4.5e+01 4.0e+04 5.0e+02]
Masked array : [500000000.0 -- -- 40000.0 500.0]