Gumowski-Mira attractor

Programming Questions

ddelgiu

in Programming Questions • 2 years ago

Hi, this is my first post on this forum and I don't know if there is a solution for my problem, also I'm new on Processing.

I worked on a code about Peter de joung attractor connecting this code to Grasshopper with an UDP receiver, you can see my code here:

http://madeincalifornia.blogspot.com/2010/12/peter-de-joung-attractor-02.html

Now I'm working to a code about the Gumowski-Mira attractor( see an actionscript here: http://actionsnippet.com/?p=9089), but for now it doesn't work.

Is anybody know how I can write correctly my code?

Here the pseudo-code:

float a,b,xn1,yn1,xn,yn,G;

float s,iterations;

void setup()

{

size (800,800);

frameRate(30);

a=0.02;

b=0.9998;

xn1=5;

yn1=0;

s=10;

iterations=20000;

G= a * x + (2 * (((1 - a) * x2) / (1 + x2)));

}

void draw()

{

background(255);

fill(175,40);

a = mouseY / 1000;

xn1 = mouseX / 30;

yn1 = 0;

for (int i= 0; i<iterations; i++){

xn = xn1;

yn = yn1;

xn1 = b * yn + G(xn);

yn1 = -xn + G(xn1);

set (280 + xn1 * s, 300 + yn1 * s, 0x000000);

i++;

}

Thx so much,

Replies(4)

Jesse Sco..

Re: Gumowski-Mira attractor

2 years ago

You haven't declared x or x2 anywhere, so that's why the IDE is giving you an error message on Line 16.

Not sure what you are trying to do on Lines 32 & 33.. ??

( Check out http://wiki.processing.org/w/ActionScript_Comparison btw)

and I think that your set function isn't going to work - check the reference for how to use it (and colors) in Processing.

ddelgiu

Re: Gumowski-Mira attractor

2 years ago

Hi Jesse,

thanks for the help. I think the main problem is to translate this math formula in a Processing Code:

where

I dont't know how I can do it...

btw thanks for your link,

I'm going to push forward my code, in order to translate the actionscript found here in a Processing code.

ddelgiu

Re: Gumowski-Mira attractor

2 years ago

Hi Jesse,

now I don't have any errors, but the code work in a strange manner, it does'nt still work correctly. Maybe are the lines 36&37, but I don't know:

float a,b,xn1,yn1,xn,yn,G1,G2,x,i;

float s,iterations;

color bla;

void setup()

{

size (800,800);

frameRate(30);

bla= color(0,150,15);

a=0.02;

b=0.9998;

xn1=5;

yn1=0;

s=10;

iterations=20000;

i=0;

G1= a * x + (2 * (((1 - a) * x*x) / (1 + x*x)));

G2= a * (x+i) + (2 * (((1 - a) * ((x+i)*(x+i)) )/ (1 + ((x+i)*(x+i)))));

}

void draw()

{

background(255);

fill(175,40);

a = mouseY / 1000;

xn1 = mouseX / 30;

yn1 = 0;

for (int i= 0; i<iterations; i++){

xn = xn1;

yn = yn1;

xn1 = b * yn + G1;

yn1 = -xn + G2;

set(int(280 + xn1 * s),int( 300 + yn1 * s), bla);

//ellipse(int(280 + xn1 * s),int( 300 + yn1 * s),10,10);

}

Is anyone ever worked on code with math function like this?

$f(x) = ax + rac{2(1-a) x^2 }{1 + x^2}$

$x_{n+1} = by_n + f(x_n)$

$y_{n+1} = -x_n + f(x_{n+1})$

ddelgiu

Re: Gumowski-Mira attractor

2 years ago

maybe I found the right way:

http://www.complexification.net/gallery/machines/henonPhase/

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