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ENH: Integer gcd function #8772
Description
Essentially, math.gcd, but operating on numpy arrays with dtype= something in the int family.
>>> a = np.arange(4)
>>> b = np.arange(10,14)
>>> np.gcd(a, b)
array([10, 1, 2, 1])
Would support broadcasting:
>>> c = 2
>>> np.gcd(b, c)
array([2, 1, 2, 1])
Might want to have a version that operates on multiple values (more than 2) on an axis of a multivariable array:
>>> d = np.arange(9).reshape((3, 3))
>>> np.gcd_along_axis(d, axis=1)
array([3, 1, 1])
(This is slightly related to #4829.)
Activity
eric-wieser commentedon Mar 11, 2017
Sounds like you're after a
gufuncforgcd(and why notlcmas well?)Although
lcmcould be implemented as a regularufunchere and then you could usenp.lcm.reduce(d, axis=...)for your second case.That wouldn't work for- wait, turns out I'm an idiot, andgcd, although you've made me thing about ways it could be made to work (#8773).gcdis associativeENH: Add gcd and lcm ufuncs