How do I combine multiple NumPy boolean arrays?

Question

I have a two-dimensional (2D) array that contains many one-dimensional (1D) arrays of random boolean values.

import numpy as np

def random_array_of_bools():
  return np.random.choice(a=[False, True], size=5)


boolean_arrays = np.array([
  random_array_of_bools(),
  random_array_of_bools(),
  ... so on
])

Assume that I have three arrays:

[True, False, True, True, False]
[False, True, True, True, True]
[True, True, True, False, False]

This is my desired result:

[False, False, True, False, False]

How can I achieve this with NumPy?

U13-Forward · Accepted Answer · 2021-10-20 09:24:08Z

2

Use min with axis=0:

>>> boolean_array.min(axis=0)
array([False, False,  True, False, False])
>>>

answered Oct 20, 2021 at 9:24

U13-Forward

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Comments

Dani Mesejo · Accepted Answer · 2021-10-20 10:41:02Z

2

Use .all:

import numpy as np

arr = np.array([[True, False, True, True, False],
                [False, True, True, True, True],
                [True, True, True, False, False]])


res = arr.all(0)
print(res)

Output

[False False  True False False]

answered Oct 20, 2021 at 10:41

Dani Mesejo

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1 Comment

Magnus Enebakk Over a year ago

Thank you! I will stick with using .min(axis=0) for now, but I see how that works as well!

Fatemeh Mansoor · Accepted Answer · 2021-10-20 09:24:05Z

0

try numpy bitwise_and =>

out_arr = np.bitwise_and(np.bitwise_and(in_arr1, in_arr2),in_arr3)

answered Oct 20, 2021 at 9:24

Fatemeh Mansoor

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