[SciPy-dev] Lambert W implementation

[Yosef Meller]

ציטוט Pauli Virtanen:
> It's faster to make it a Ufunc -- np.vectorize will likely sacrifice 
> much of the speed gained from using Cython since it's going to box and unbox
> numbers in Python floats. There's an example how to do Ufuncs in
> Cython here:
> 
> 	http://projects.scipy.org/scipy/browser/trunk/scipy/special/orthogonal_eval.pyx

Thanks for the example, it really helped.

> If you get it done, please post the result (preferably, create
> a ticket on http://projects.scipy.org/scipy/ and attach the file) and
> we'll integrate it in scipy.special. If you also write tests, that'd
> be great!

Here it is, with the tests:
http://projects.scipy.org/scipy/ticket/1049

The doc-string is not exactly in the doc format of SciPy, but I don't 
have time to work on it right now.

> Note that newer Cythons also have support for native complex numbers, so
> you can do
> 
> 	cdef double complex a = ...
> 
> The same algorithm probably works both for real and complex parameters.

Thanks. Took some hunting around to get all the complex machinery to 
work, but it's finally done.

Yours,
Yosef.