[Numpy-discussion] Infinity definitions

[Travis E. Oliphant]

Bruce Southey wrote:
> Hi,
> Since we are discussing namespace and standardization, I am curious in 
> why there are multiple definitions for defining infinity in numpy when 
> perhaps there should be two (one for positive infinity and one for 
> negative infinity). I really do understand that other people have use of 
> these definitions and that it is easier to leave them in than take them 
> out. Also, it is minor reduction in namespace because I do know that 
> much of the namespace is either defining variables (like different 
> floats and complex numbers) or mathematical functions (like logs and 
> trig functions).
>
> Currently we have:
> numpy.Inf
> numpy.Infinity
> numpy.inf
> numpy.infty
> numpy.NINF
> numpy.PINF
>
> Most of these are defined in numeric.py: 'Inf = inf = infty = Infinity = 
> PINF'
> In the f2py/tests subdirectories, the files return_real.py and 
> return_complex.py uses both 'inf','Infinity'.
> The only occurrence of NINF and PINF are in core/src/umathmodule.c but I 
> don't see any other usage.
> There does not seem to be any use of 'infty'.
>   
I think this is a product of bringing together a few definitions into 
one and not forcing a standard.

numpy.inf
numpy.nan

should be used except for backward compatibility.

-Travis