This may be waaay off topic, but if you could use Python then this implementation of the game of life may have something to teach - it's really blindingly fast!
http://golly.sourceforge.net/ enjoy, John On Mar 25, 4:15 am, Matthew Kerle <[email protected]> wrote: > TL;DR we're writing a Mandelbrot set viewer and need to dive deeper. > BigDecimal sucks. help! > > So... My friend wrote a mandelbrot set viewer in Java (with Netbeans =D ) > using floats, it's pretty nice and lets you pan around and zoom and the > performance is not too bad, but after a while you hit the precision limit of > float (image pixellates out) so we swapped over to double and got a bit > deeper. > > The problem is now we want to go deeper than double lets us (step 6 > here<http://en.wikipedia.org/wiki/Mandelbrot_set#Image_gallery_of_a_zoom_s...>). > We tried implementing with BigDecimal but the performance absolutely crapped > out, like 100x worse, you die waiting for a single frame to render even with > precision turned way down (God help if you don't set a MathContext!!). After > googling around it looks like the problem is BigDecimal, it's optimised for > precision over speed. we don't care very much about precision, we just need > enough to get our pretty colours :-) Speed is more of a concern, although > obviously we're not realistically expecting float/double type speed from > arbitrary-precision arithmetic, but a slowdown of 2-5x would be fine, 10x + > starts getting depressing though... > > Other methods of performance tuning we're looking at: > - firstly progressive rendering (eg, do 100 iterations, draw an image, then > next 100 and so on to limit) > - scale-dependant implementation (eg go from float to double to ? as you > zoom in) > - multi-threading (split the image up and hand each portion off to a core, > not sure best way to configure this, thread per core?) > - caching (not sure best strategy for this, store result for each point with > iteration count or image directly? cache would get HUGE, but don't care...) > > I've found the ApFloat library <http://www.apfloat.org/apfloat_java/> which > looks pretty cool. but haven't had a chance to run some comparison runs with > it against BD yet (darn day job!!). > > Just wondering if anyone else has any experience with this domain or any > pointers? it's been a few years since uni and my number theory is a bit > rusty (one of the reasons we're playing with this...). mandelbrot uses > T(n+1) = n^2 + first term, so maybe we can do some optimisations by using > operating on integers and storing the precision separately? (obviously this > is what BD does already, but we only want a narrow slice of what it does...) > > incidentally, found Fast Fractal, it's a closed-source > windows-only<http://www.fastfractal.com/>program which purports to > have GPU acceleration for fractal viewing. I tried > it out and wasn't impressed, but then it couldn't detect my graphics card so > GPU acceleration wasn't enabled (low-rung Toshiba Satellite laptop). Any > decent GPU accelerated mandelbrot viewers out there for linux? > > cheers! > matt. -- You received this message because you are subscribed to the Google Groups "The Java Posse" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/javaposse?hl=en.
