complex ldexp

[hamzaelsaawy]

Defining ldexp for complex type as a map over individual elements

[c42f]

Neither C++ nor numpy seem to support complex ldexp - can you find out why that is?

[c42f]

I'm not sure it's worth just copying the tests from the the float versions of ldexp wholesale, given that the implementations are tightly coupled. It might be better just to test a few examples, given that complex ldexp inherits its behavior directly from the float version.

[hamzaelsaawy]

I think ldexp in math.h originally wrapped an assembly instruction and there was no similar instruction for complex numbers. (Though interestingly the C++ implementation has a generic for integers).

And I will update the tests hopefully soon.

[c42f]

Sure, I'm just wondering if numpy did this on purpose; they do state very explicitly/authoritatively in their documentation that "Complex dtypes are not supported, they will raise a TypeError.".

Ok, so after digging into the numpy history, it appears there's no good reason for this. Travis Oliphant added ldexp for normal floats way back in numpy/numpy@d91b5b9. The documentation eventually caught up in numpy/numpy@87fa5ae. The answer could very well be "it was annoying to add to the C code so nobody bothered" :-)