From: Lars Haugseth <njus@...>
Date: 2009-02-18T00:15:02+09:00
Subject: Re: [SUMMARY] Mathematical Image Generator (#191)

* Daniel Moore <yahivin@gmail.com> wrote:
> 
> No one got really crazy with performance and created a lookup table
> for trigonometric functions, but that may be one way to save cycles,
> especially when creating much larger images.

After I posted my code here, I did some quick experimentations involving
"caching" of sub-expressions not involving x as a factor by calculating
those outside the inner loop, storing them in a hash and looking up the
value from the hash inside the inner loop. However, in my experience it
was faster to actually compute the simple expressions (Math.sin(y),
y * y, etc.) than looking them up in a hash. I guess such caching could
speed things up a little if one was to cache more complex expressions
involving just one of the dimensions, but I deemed it too much effort
for too little gain to investigate further.

Thank you Daniel.

-- 
Lars Haugseth

"If anyone disagrees with anything I say, I am quite prepared not only to
 retract it, but also to deny under oath that I ever said it." -Tom Lehrer