[Numpy-discussion] Can't get ufunc to work for integers

Pauli Virtanen pav@iki...
Thu Jul 22 11:14:27 CDT 2010

Thu, 22 Jul 2010 08:49:09 -0700, John Salvatier wrote:
> I am trying to learn how to create ufuncs, and I got a ufunc to compile
> correctly with the signature int -> double, but I can't get it to accept
> any arguments. My function is testfunc and I used NPY_INT as the first
> signature and NPY_DOUBLE as the second signature. What should I look at
> to figure this out?

I think you need to specify NPY_LONG instead of NPY_INT -- the NPY_INT is 
IIRC sort of a "virtual type" that you can use when creating arrays, but 
no array is ever of type NPY_INT, since it maps to either NPY_LONG or 
whatever the C "int" type happens to be.

Maybe someone can correct me here, but AFAIK it goes like so.

Pauli Virtanen

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