Re: [boost] Relational Template Library

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2005-10-11 14:55:59

"Calum Grant" <calum_at_[hidden]> wrote

> > BTW, the file you provided is very interesting.  I played
> > with it yesturday, but so far my results are pretty slow (no
> > wonder -- I have to consider more than 400,000,000 possible
> > combinations).  One of possible reasons is the lack of
> > co-processor on my PC (quite a bit of math is done), but I
> > also found some RTL inefficiencies (as I said, we haven't
> > spend a lot of time on the optimization yet).  I will do some
> > more research and then provide the results.  Will probably
> > take a few days to a week.
>
> You could instead sort on the square of the distance - saving you one
> square root per iteration, and since you don't need square root, you can
> just work with integers.  I'm just intrigued how you are going to fit
> 400,000,000 items into an index in memory!!

I never wanted to do this -- I index the resulting groupby, not the
crossproduct.  But you are right I can do something more intellegent -- this
particular task does allow this.

Regards,
Arkadiy