[Numpy-discussion] Seeking advice on crowded namespace.

Bruce Southey bsouthey@gmail....
Tue Aug 17 15:43:41 CDT 2010


  On 08/16/2010 10:00 PM, Charles R Harris wrote:
> Hi All,
>
> I just added support for Legendre polynomials to numpy and I think the 
> numpy.polynomial name space is getting a bit crowded. Since most of 
> the current functions in that namespace are just used to implement the 
> Polynomial, Chebyshev, and Legendre classes I'm thinking of only 
> importing those classes by default and leaving the other functions to 
> explicit imports. Of course I will have to fix the examples and maybe 
> some other users will be inconvenienced by the change. But with 2.0.0 
> in the works this might be a good time to do this. Thoughts?
>
> Chuck
While I don't know a lot about this so things will be easily off base.

In looking at the names, I did see many names that seem identical except 
that these work just with one type of polynomial.

Obviously cheb2poly and poly2cheb are the conversion between the 
polynomial and Chebyshev types - similarly leg2poly and poly2leg for the 
polynomial and Legendre classes. But none between Chebyshev and Legendre 
classes. Would it make more sense to create a single conversion function 
to change one type into another instead of the current 6 possibilities?

Similarily there are obviously a very similar functions that just work 
with one polynomial type so the functionality is duplicated across each 
class that could be a single function each:
chebadd    legadd    polyadd
chebder    legder    polyder
chebdiv    legdiv    polydiv
chebdomain    legdomain    polydomain
chebfit    legfit    polyfit
chebfromroots    legfromroots    polyfromroots
chebint    legint    polyint
chebline    legline    polyline
chebmul    legmul    polymul
chebmulx    legmulx    polymulx
chebone    legone    polyone
chebroots    legroots    polyroots
chebsub    legsub    polysub
chebtrim    legtrim    polytrim
chebval    legval    polyval
chebvander    legvander    polyvander
chebx    legx    polyx
chebzero    legzero    polyzero

However, I doubt that is worth the work if the overall amount of code is 
not reduced. For example, if you create a overall function that just 
calls the appropriate add function for that type of polynomial then I do 
not see any advantage in doing so just to reduce the namespace.
If you can argue that is very beneficial to the user of polynomial 
functions then that could put a different spin on doing that.

While I would have to check more carefully (as I don't have time now), 
aren't chebadd, legadd and polyadd essentially the same function?
That is, can you send a Legendre polynomial to the same Chebysnev 
function and get the same answer back?
If so then these functions should be collapsed into one for numpy 2.0.


Just my 1 cent on that,
Bruce


More information about the NumPy-Discussion mailing list