[SciPy-dev] MCMC, Kalman Filtering, AI for SciPy?

Fernando Perez Fernando.Perez at colorado.edu
Thu Sep 30 11:42:11 CDT 2004


Perry Greenfield schrieb:
> On Sep 30, 2004, at 3:40 AM, eric jones wrote:
> 
>>I don't like the replication idea very well.  I think things should 
>>live in one place.  Otherwise people will wonder if two functions that 
>>are actually the same have different purposes, implementation, etc.
>>
> 
> I agree with this sentiment. Use the search tool to find out where the 
> one "true" item lives,
> but don't use aliasing within the package hierarchy.

Fair enough :)

> This seems like a good idea as well. I don't see anything wrong with 
> using
> something like:
> 
> import numarray as na
> 
> to make the code (and particularly expressions) more concise. It still 
> prevents the above
> mentioned problems.

I've gotten into the habit of always writing:

import Numeric as N

everywhere, and it works quite well.  It prevents the problems already 
mentioned, and it also allows the following kind of optimization:

def foo():
   dot = N.dot
   for i in longlist:
      dot(a,b)...

since locals are much faster than globals, if you have some long loop which 
repeatedly accesses one of these functions, localizing it may pay off.  If 
Numeric were imported as *, you'd need to change the local name, since:

dot = dot

wouldn't work.

Cheers,

f




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