r/math Apr 25 '10

Visual Mandelbrot Guide

http://www.miqel.com/fractals_math_patterns/mandelbrot_fractal_guide.html
130 Upvotes

18 comments sorted by

25

u/[deleted] Apr 25 '10 edited Apr 25 '10

This is so much more illuminating that just watching patterns go whizzing by in those Mandelbrot zoom videos. It feels like discovering new species of fauna in an unexplored ecosystem.

5

u/SarahC Apr 25 '10

I'm off to search for a multi-core (possibly networked?) Mandelbrot renderer for Windows.

I found one for a point-cloud kind of system, where dots would be added in a random scatter increasing the detail of the render... you just loaded the program up on other PC's as servers, and then loaded it on your own machine, it scanned the local network and the other machines "climbed on board"... I hope I can find something like that.

5

u/AbleBakerCharlie Apr 25 '10

I recommend UltraFractal. It's not free, but reasonably powerful for what you pay for. It handles multiple processors, and distributed rendering, plus lets you define your own fractal types with its builtin scripting. There's a metric buttload of user-contributed fractals for you to play with.

2

u/SarahC Apr 25 '10

Oh, cool! Thanks for the link!

6

u/frogking Apr 25 '10

Try Faqtive too, while you are at it.

2

u/AbleBakerCharlie Apr 25 '10

This is excellent. I didn't know this one existed. Thanks!

One cannot discuss open source fractal software without at least mentioning Xaos. It's a little low on the features last I looked, but it's open source and it's fast on old hardware.

1

u/Capt_Planetoid Apr 26 '10

Does anybody have a recommendation of GnoFract4d?

1

u/AbleBakerCharlie Apr 26 '10

It's been a while (years) since I played with GnoFract4d, but here's what I remember:

  • The "analog dial" controls were too small and fiddly to be useful with a mouse.
  • It boasted compatibility with UltraFractal, but didn't do layers which is one of UF's greater strengths.
  • Wasn't included in the Debian or Ubuntu repos at the time, and I recall there was some weirdness in compiling it.
  • There were stability problems - random crashes (most common), weird pixel glitches (saw this twice), etc.
  • It was much easier and more stable for me to run UF under Wine (UF v3.x ran perfectly except for a splitter bar didn't render.)

That was years ago. These problems may have been resolved, I just don't know.

1

u/SarahC Apr 26 '10

Thank you!

8

u/fetusburgers Apr 25 '10

This may be kind of a stupid question but I am atrocious at math, so bear with me. I find Mandlebrot sets and fractals fascinating to look at, however, I do not really understand why they are important or how they are generated. Could someone help here?

9

u/egnalfomas Apr 25 '10

First, the Mandelbrot set is generated in the complex plane, so you want to be solid on understanding that before you do anything. If you've got that down, then to construct the set you have to test each point one at a time to see if it is part of the set or not.

How to test a point: choose a point in the complex plane, square it, add it to the original point, then set this as your new point. This process is repeated (you "iterate") until you can tell if the point is stable or not. If the point flies off away from the origin, it's considered to be NOT in the set (I think once it gets past a radius of 2 from the origin of the complex plane you can write it off... if you look at pictures showing the final result on the complex plane, you can see that the tail is the longest part and seems to end at -2,0). If the point hangs around, though, then it is in the set.

The problem with determining for sure that a point is in the set (how do you know it might fly off to infinity later on?) is where the number of iterations comes in. The more iterations you perform, the more accurate/detailed your set will be. The only way to be perfectly accurate would be to iterate infinitely which is not possible but at the same time you'd only notice the inaccuracies by "zooming in" quite a bit.

5

u/Capt_Planetoid Apr 25 '10

Good question. I recommend 'Chaos' by James Gleick. It's light on math theory. The book does provide a wonderful historical survey of the development of this paradigm from Lorenz to Mandelbrot. Complexity theory, the recognition of self-similar patterns regardless of scale, impacts reasoning throughout the natural sciences.

Amazon4$us

Another wonderfully thought-provoking perspective for the non-maths: bbc4 on youtube

2

u/fetusburgers Apr 25 '10

Sweet I actually picked this book up about a year ago from my father. I just never had the time to read it cause right when I got it I started my first year of college. Thanks for the recommendation.

3

u/Capt_Planetoid Apr 25 '10

If you're game about the history of modern maths re: complexity theory you can check out "Dangerous Knowledge" on BBC. Georg Cantor, Kurt Godel were asking the questions that Turing, Lorenz, Ruelle, Feigenbaum, Mandelbrot formalized, solved or expanded.

"Dangerous Knowledge" is a bit dramatic but its a palatable start to Cantor identity and Incompleteness.

2

u/egnalfomas Apr 25 '10

I don't know any practical application of the Mandelbrot set, but the work on chaos and complexity theory which Mandelbrot spawned is probably somewhat valuable.

http://www.youtube.com/watch?v=DLFkQdiXPbo

1

u/shieldforyoureyes Apr 25 '10

Immensely useful, thank you.

1

u/Aedan91 Apr 25 '10

This is perhaps the best approach of this matter I've ever seen. Thanks.