attractor_generator

Generate colorized representations of De Jong attractors.

Installation

Before using the program, you need two python libraries:

• pillow
• numpy

To install them, use these lines in command line:
pip install pillow and pip install numpy

Basic usage

To generate attractors, first compile make_matrix.c and run *.out file with 5 (or 7) arguments.

example: ./make_matrix -2.3 1.5 -1.9 2.1 250000000 1200 1200

Then run colorize.py: python colorize.py

Your picture should appear inside 'attractor_pictures' directory.

Arguments explained

Usage: make_matrix.exe a b c d iters width(optional) height(optional)

• a, b, c, d [float64] are parameters for the attractor equations:
     x_n+1 = sin(a*y_n) - cos(b*x_n)
     y_n+1 = sin(c*x_n) - cos(d*y_n)
• iters [int64] is number of iterations
• width and height [int32] are optional; by default they are set to 1100 each.

You can also run make_matrix.exe without arguments for explanation of every argument.

How to colorize

This is the creative part of the process. It's more of a experiment in the end.
To change colors of the attractor, you should open the file colorize.py in your favourite text editor and change the code manualy. Find the function calc_color1:

def calc_color1(x, y, value, width, height):
    w = x*1.0/width
    h = y*1.0/height
    i = 255
    j = 255
    k = 255
    #calculate r g b values
    r = int((2*i/pi)*atan(value/i))
    g = int((2*j/pi)*atan(value/j))
    b = int((2*k/pi)*atan(value/k))
    return (255-r, 255-g, 255-b)

To change the colors, you can change 'i' 'j' and 'k' values.
You can also multiply value for certain color with 'w' or 'h' and this color will change horizontally or vertically.
example_1: r = int((2*i/pi)*atan(w*value/i))
More examples and pictures will be added to wiki!

Don't forget to save and run colorize.py again!