CHAOS CONTROL

terrain.py

import numpy as np
from scipy.ndimage.filters import generic_filter
from random import random
import matplotlib.pyplot as pp
import matplotlib

grid = np.random.rand(128, 128)

weights = [ 1, 2, 1,
            2, 3, 2,
            1, 2, 1, ]

p_initial = 1
p_final = 0.3
chaos_control = 0.95


def update(arr):
    new = np.average(arr, weights=weights)
    if np.random.rand() < new:
        new += np.random.rand()/10 * multiplier
    else:
        new -= np.random.rand()/10 * multiplier
    return new
    
def maprange(x, a, b, c, d):
    return (x - a) / (b - a) * (d - c) + c

pp.set_cmap(matplotlib.cm.get_cmap('terrain'))
p_chaos = p_initial
while True:
    chaos = np.random.rand() < p_chaos
    multiplier = [1, -1][chaos]
    generic_filter(grid, update, size=(3,3), output=grid, mode='wrap')
    np.clip(grid, 0, 1, out=grid)
    pp.matshow(grid, fignum=0)
    pp.title(str(p_chaos))
    pp.pause(0.001)
    pp.cla()
    if p_chaos > p_final:
        p_chaos *= chaos_control
    if p_chaos < p_final:
        p_chaos = p_final