[Numpy-discussion] A little help please?

[Travis E. Oliphant]

Neal Becker wrote:
> My user-defined type project has mostly gone well, but I'm stuck on
> mixed-type arithmetic.
>
> I have 2 types: cmplx_int32 and cmplx_int64.  I have added basic arithmetic
> for those types, and for mix of those arrays and their respective scalars. 
> But mixed arithmetic only partly works
This is an area that needs testing and possible fixes.   The relevant 
code is in ufuncobject.c (select_types) and in multiarraymodule.c 
(PyArray_CanCoerceScalar).    If you can go through that code you may be 
able to see what the problem is and let us know. 

I tried to support this kind of thing you are doing, but I'm not sure 
how well I succeeded because I didn't have time or the code to test it 
with.  Thus, there is still some work to do.

The fact that radd is not called is because ufuncs try to handle 
everything (the ufunc is more general than just the functions with "r" 
prefixes.   I think one problem may be due to the fact that the first 
argument to a ufunc is the one that defines the search for the correctly 
registered function and there may be no code to allow other arguments to 
direct the search should that one fail. 

I'm actually pleased you've gotten this far.   I'll keep trying to help 
as I get time.

-Travis O.