NumPy布尔数组警告? [英] NumPy boolean array warning?

问题描述

我有几个numpy数组，比如说a，b和c，并创建了一个mask应用于所有数组.

I have a few numpy arrays, lets say a, b, and c, and have created a mask to apply to all of them.

我正试图掩盖他们

a = a[mask]

其中mask是bool数组.值得注意的是，我已经证实了这一点

where mask is a bool array. It is worth noting that I have verified that

len(a) = len(b) = len(c) = len(mask)

我得到一个相当神秘的声音警告:

And I am getting a rather cryptic sounding warning:

FutureWarning: in the future, boolean array-likes will be handled as a boolean array index

推荐答案

False == 0，并且True ==1.如果掩码是列表而不是ndarray，则可能会出现一些意外行为:

False == 0, and True == 1. If your mask is a list, and not an ndarray, you can get some unexpected behaviour:

>>> a = np.array([1,2,3])
>>> mask_list = [True, False, True]
>>> a[mask_list]
__main__:1: FutureWarning: in the future, boolean array-likes will be handled as a boolean array index
array([2, 1, 2])

该数组由a [1]，a [0]和a [1]组成，就像

where this array is made up of a[1], a[0], and a[1], just like

>>> a[np.array([1,0,1])]
array([2, 1, 2])

另一方面:

>>> mask_array = np.array(mask_list)
>>> mask_array
array([ True, False,  True], dtype=bool)
>>> a[mask_array]
array([1, 3])

警告告诉您，最终a[mask_list]将为您提供与a[mask_array]相同的功能(这可能是您希望它首先为您提供的功能.)

The warning is telling you that eventually a[mask_list] will give you the same as a[mask_array] (which is probably what you wanted it to give you in the first place.)

这篇关于NumPy布尔数组警告?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！