Add sqrt and power functions to operate on pdarray

[milthorpe]

Square root and power operations are useful; this enhancement would add them as functions to the arkouda module alongside exp etc.

arkouda.sqrt would be a simple element-wise operation (like exp).
arkouda.power would have a similar interface to numpy.power, accepting as the second argument either a scalar value to which all elements of the first array are raised, or an array of powers to which corresponding elements of the first array are raised.

[milthorpe]

Immediately closing this issue after discovering that Arkouda has already implemented the ** operator :-)
E.g. the following work just fine:

>>> ak.array([2,0,-1])**0.5
array([1.4142135623730951 0 nan])
>>> ak.array([10,5,2])**ak.array([2,3,4])
array([100 125 16])

[Ethan-DeBandi99]

@milthorpe - I am reopening this. Since your first thought was to use .sqrt and .power I am going to create those functions that will essentially be aliases for the ** operator, but will at least exist.

[milthorpe]

If it fits with the Arkouda design philosophy, sure! As a little more background - you have probably guessed this already - I am attempting a 'verbatim' translation of existing numpy code to use Arkouda, and for whatever reason sqrt and power seem to be the preferred numpy style.

[Ethan-DeBandi99]

@milthorpe - if it is the preferred style by numpy, Arkouda should definitely include it. I already added the code. I already put up a PR for this so once the rest of the team reviews it will be merged and will be in the next release. Thanks for bringing this up!