Support numpy ufuncs for Quantities about ilaff HOT 2 OPEN

I've just come across an issue with numpy's gradient. I can fix it for my use case, but not for the general.

f = np.array([1, 2, 4, 7, 11, 16], dtype=float) * units.one
print( np.gradient(f) )

gives the error

File "analysis.py", line 151, in getW0
print( np.gradient(f) )
File "<array_function internals>", line 5, in gradient
File "/home/ryan/Documents/GithubProjects/ILAFF/ILAFF-F/src/ilaff/units/quantity.py", line 323, in array_function
return func_units(args, kwargs)
File "/home/ryan/Documents/GithubProjects/ILAFF/ILAFF-F/src/ilaff/units/quantity.py", line 1057, in wrapper
raise RuntimeError(f"Return value of {func.name} does not match expected format")
RuntimeError: Return value of gradient does not match expected format

If I specify the spacing for the gradient (between f values), i.e.

f = np.array([1, 2, 4, 7, 11, 16], dtype=float) * units.one
print( np.gradient(f,1) )

it works. However this does not seem to apply to the two-dimensional case:

    dx = 2. * units.one
    y = [1., 1.5, 3.5] * units.one
    f = np.array([[1, 2, 6], [3, 4, 5]], dtype=float) * units.one
    print( np.gradient(f, dx, y) )

which has the same error as before.

The first of these problems can be fixed by changing the gradient array func in quantity.py to

@_array_func(numpy.gradient)
def gradient(f: Quantity, *varargs: Quantity, axis: Optional[Union[int, Sequence[int]]] = None, edge_order: int = 1) -> List[Tuple[Dimension, Scale]]:
    if len(varargs) == 1:
        shape = numpy.shape(f.value)
        N = len(shape)
        return [_divide_units(numpy.gradient, f, varargs[0], labels={1: "spacing"})] * N
    elif len(varargs) == 0:
	shape = numpy.shape(f.value)
	N = len(shape)
        return [_divide_units(numpy.gradient, f, labels={1: "spacing"})] * N
    else:
        return [_divide_units(numpy.gradient, f, arg, labels={1: "spacing"}) for arg in varargs]

I.e. the len(varargs) == 0 section.

from ilaff.

Nice report, I've fixed both problems in 20a17d6

from ilaff.