numpy.minimum for complex numbers

Question

numpy.minimum does not seem to work for complex numbers:

np.minimum(5+3*1j,4+30*1j)
(4+30j)

I want to keep the value with the maximum magnitude. It only compares the real part. Any other function for elementwise minimum comparison? MATLAB min does work with complex numbers. Thanks

Answer 1

If you want to compare complex numbers by magnitude, you can use built-in abs and then compare results:

>>> np.minimum(abs(5+3*1j),abs(4+30*1j))
5.830951894845301

To get a minimal initial number instead of its magnitude, use argmin:

>>> nums = [5+3*1j, 4+30*1j]
...
>>> nums[np.abs(nums).argmin()]
(5+3j)

Answer 2

You can use np.where and np.abs

Suppose you have

vals1 = [4+30*1j, 7+3*1j, 4+30*1j]
vals2 = [5+3*1j, 6+3*1j, 5+3*1j]

then

>>> np.where(np.abs(vals1) > np.abs(vals2), vals2, vals1)
array([5.+3.j, 6.+3.j, 5.+3.j])