From: Marnen Laibow-Koser <marnen@...>
Date: 2009-11-16T01:42:38+09:00
Subject: Re: Trajectories

Shot (Piotr Szotkowski) wrote:
> Marnen Laibow-Koser:
> 
>> Yeah, I tried longer runs as well and saw larger differences.
>> I question the applicability of those to actual programs, though;
>> even computationally intensive programs are going to be spending lots
>> of time doing things other than number crunching.
> 
> To clarify, I also believe BigDecimals should be used by default (when
> one’s serious about the results’ acccuracy) until they are actually
> determined to be a performance bottleneck. 

Yes, this is what I was trying to say.

> There even was a motion
> to make them the language default, but the resolution was that
> the performance cost was way too large, and that most (if not all)
> other general-purpose languages default to IEEE floats for exactly
> this reason.
>

Interesting.

>> Besides, what good are fast calculations if they're wrong?
> 
> Well, if they’re slightly wrong, but a couple of times faster, they
> might be good enough; the previous example in this thread was IMHO
> a good one – you don’t usually need accurate float arithmetics in
> action games, but you do often care for the performance gain.

Perhaps.  I would think you actually would want accurate math, but it 
depends on the game.

> 
> — Shot, who wouldn’t mind if Ruby defaulted to BigDecimals :)

Likewise.

Best,
--
Marnen Laibow-Koser
http://www.marnen.org
marnen@marnen.org
-- 
Posted via http://www.ruby-forum.com/.