Python in game development? + recFib

[Christian Tanzer]

Mike Fletcher <mfletch at tpresence.com> wrote:

> The problem with that particular implementation (elegant as it is) is that
> you wind up creating a cache of potentially hundreds of thousands of
> integers when you only need two for the next value (as far as I can see,
> anyway) here is a somewhat faster version of the same algorithm when you're
> dealing with fairly large numbers (such as fibonacci (100000)).

Well, I'm not in the business of playing with x-large fibonacci
numbers. And sure, one should adapt one's algorithm to the problem
to be solved.

You might overrate the negative effects of using lists of 100000
elements, though. For instance, on my system with 160MB main memory it
hardly makes any visible difference whether you use `xrange (2, n+1)'
or `range (2, n+1)' for n==100000 -- procmeter just shows a tiny
dip in free memory for the `range' version (the speed of your
fibonacci2 is the same for both `range' and `xrange', too).

My-original-point-in-this-thread-wasn't-really-optimization-
of-fibonacci-algorithms, ly
Christian

-- 
Christian Tanzer                                         tanzer at swing.co.at
Glasauergasse 32                                       Tel: +43 1 876 62 36
A-1130 Vienna, Austria                                 Fax: +43 1 877 66 92