np.dot is not supported by scimath

[awa5114]

I came from he pint package, disappointed with its numpy support to scimath in hopes that the UnitArray could present some interesting possibilities. Unfortunately this is not the case. I would like to run a unit-aware dot product using 2 unit arrays, but this won't work:

a = UnitArray(np.linspace(0, 5, 6), units="cm")
b = UnitArray(np.linspace(0, 9, 6), units="sec")
c = np.dot(a,b)

type(c) shows that this is a numpy.float64 object and not a UnitArray of length 0 or a UnitScalar as I would expect. This makes it difficult for me to see the use of UnitArrays since they currently only appear to support element wise multiplication in numpy...

Is there a concise way of doing a unit-aware dot product with scimath? If so how? If not how to implement it?

[corranwebster]

We didn't have the use-case for dot with UnitArrays when we wrote the code, but you are right that it makes sense. Fixing would be just a matter of adding a dot method to the UnitArray class that did the right thing with the units. Unfortunately at Enthought we don't have bandwidth for working on SciMath in the near-term, but we would happily accept a pull request implementing this feature.

In the interim, the best work-around for you in your own code is possibly to monkeypatch UnitArray with a dot product method:

def dot(self, b):
    ...

UnitArray.dot = dot