Request : Provide argmin and argmax functions

[hprodh]

The argmin and argmax functions would be convenient among the set of einx functions.

It seems obvious, but they should work just like min and max except that they would return positional indexes instead of values.

[fferflo]

Hi @hprodh,

argmin and argmax functions are now supported by einx. Here are a couple of examples:

x = np.random.rand(20, 30, 40)
y = einx.argmax("a b [c] -> a b", x) # 1D argmax
y = einx.argmax("a b [c] -> a b [1]", x) # 1D argmax
y = einx.argmax("a [b c] -> a [2]", x) # 2D argmax

Closing this issue, feel free to reopen if anything isn't working as expected.