A Retina-ready version of the deJong Attractor

http://jashkenas.s3.amazonaws.com/misc/deJong/deJong.html

by jashkenas • 14 years ago

29 14 14 years ago

jashkenas.s3.amazonaws.com

Jacob4u2• 14 years ago

I noticed that dragging around causes the graph to change. I know I should just look at the source, but can someone tell me what inputs the dragging changes for the computation? Also, bonus points for some cool drags I can do that you notice.

jashkenas5• 14 years ago

This is the bit that records the dragging change in mouse position:

http://jashkenas.s3.amazonaws.com/misc/deJong/docs/deJong.ht...

This is the bit that seeds the sketch at the last recorded mouse position:

http://jashkenas.s3.amazonaws.com/misc/deJong/docs/deJong.ht...

jashkenas5• 14 years ago

This is a repost (the Retina bit is new), but for those who haven't seen it before, you can share particular initial seeds by clicking on the "Permalink" button.

An example Retina seed: http://jashkenas.s3.amazonaws.com/misc/deJong/deJong.html#52...

Annotated source here: http://jashkenas.s3.amazonaws.com/misc/deJong/docs/deJong.ht...

One interesting question will be if anyone finds a single seed that works well for both regular and Retina versions.

mvr_• 14 years ago

The best thing about this toy is that, no matter where you click, you get a beautiful result.

The only thing missing is arrowkey controls to bump around a pixel at a time, so you can better explore an interesting region of the space you've found.

stianan3• 14 years ago

Could someone explain what an attractor is? I looked it up on Wikipedia, but I don't understand how these shapes benefit from the definition given there.

jashkenas5• 14 years ago

The Wikipedia explanation is a fine one. To simplify -- it's when you observe a variable moving through through a space. In programming this means taking a coordinate or set of coordinates, and repeatedly feeding it into a function that will move the coordinates to a new location.

In this case, the heart of the function is:

    x = ((sin(xSeed * y) - cos(ySeed * x)) * width * 0.2) + width / 2

... and the same for "y".

(http://jashkenas.s3.amazonaws.com/misc/deJong/docs/deJong.ht...)

In our attractor, every time the coordinate pair lands on a new spot, that spot is exposed to a little bit of light.

What you can do for "x" and "y", you can also do for "z". If you generalize the deJong attractor into 3 dimensions, it looks like this:

https://www.youtube.com/watch?v=PrXe4RwtZpQ

elteto• 14 years ago

Could you explain why is it significant that points seem to cluster around some specific trajectories / coordinates?

stianan3• 14 years ago

So an attractor is the image of a recursively defined function?

jlong_gt• 14 years ago

what is this?!

samstokes• 14 years ago

FWIW, in Firefox (15) I just see a white square. Works fine in Chrome.

A Retina-ready version of the deJong Attractor

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