numpy.union1d — NumPy v1.11 Manual (original) (raw)
numpy.union1d(ar1, ar2)[source]¶
Find the union of two arrays.
Return the unique, sorted array of values that are in either of the two input arrays.
| Parameters: | ar1, ar2 : array_like Input arrays. They are flattened if they are not already 1D. |
|---|---|
| Returns: | union1d : ndarray Unique, sorted union of the input arrays. |
See also
numpy.lib.arraysetops
Module with a number of other functions for performing set operations on arrays.
Examples
np.union1d([-1, 0, 1], [-2, 0, 2]) array([-2, -1, 0, 1, 2])
To find the union of more than two arrays, use functools.reduce:
from functools import reduce reduce(np.union1d, ([1, 3, 4, 3], [3, 1, 2, 1], [6, 3, 4, 2])) array([1, 2, 3, 4, 6])