Dynamic or not?

[Tim Roberts]

rishiyoor at gmail.com wrote:
>
>I'm trying to write a program that will find the distance between two
>groups of points in space, which have cartesian co-ordinates X,Y and
>Z.
>
>I need to find the distances between each point in one group and every
>point in the other group. So if group 1 has 6 points and group 2 had 8
>points, I will calculate 6 x 8 = 48 distances. But I do not know the
>number of points the user will want to use. It is typically between 50
>and 500 in both groups combined, but may be more. Since the memory
>required for the distances will be much larger than the points
>themselves, I am wondering if I will have to allocate memory
>dynamically or if there are easier ways of solving such problems in
>Python.

Python already allocates memory dynamically.  With 500 in each group,
you'll have 250,000 distances.  If you use floating point, that's only 2
megabytes.  Piece of cake.  With 1,000 in each group, it's 8 megabytes.
Still no sweat.

What are you going to do with these distances?  Why do you need them all in
memory?
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.