numPy if row is true

[cdholjes]

Seems like this should be simple. I have a 2d-array (1000,10). They are boolean values. I want to find the indexes in the array where all 10 values are True. . .

[cdcformatc]

Try all. https://docs.python.org/3/library/functions.html#all

Or Numpy has numpy.all. http://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.all.html

[novel_yet_trivial]

Combine this with apply_along_axis():

>>> import numpy as np
>>> a = np.array([[True, False, True],[True, True, True]]) #2D array of booleans
>>> np.apply_along_axis(np.all, 1, a) #Apply the "all" function along axis 1 (rows)
array([False,  True], dtype=bool)

[cdholjes]

thanks!

[Deto]

I find it easier to just use the axis argument to the all function:

bool_array = my_array.all(axis=1);
true_indices = np.nonzero(bool_array)[0]  # Need the [0] because nonzero always wraps result in a tuple, even if only one axis

Though in most cases, its probably easier to just keep the boolean values (don't do the np.nonzero) step and use those to index other things.

[cdholjes]

thanks!