dither_brot.py

from numba import jit
import matplotlib.pyplot as plt
import numpy as np
from matplotlib import cm

@jit
def mandelbrot(c,maxiter):
    z = c
    la = 0
    t = 16
    for n in range(maxiter):
        if abs(z) > t:
            #d = (4 - abs(z))
            #r = np.random.normal(scale=0.5)
            d = (t - abs(z)) * abs(np.random.rand()) / t / 8
            #i = n + d
            #return i #np.sqrt(i)
            return abs(z) / maxiter
        z = z*z + c
        la = abs(z)
    d = abs(np.random.rand())
    i = abs(np.angle(z)) / np.pi * maxiter + d
    return i

@jit
def mandelbrot_set(xmin,xmax,ymin,ymax,width,height,maxiter):
    r1 = np.linspace(xmin, xmax, width)
    r2 = np.linspace(ymin, ymax, height)
    n3 = np.empty((width,height))
    for i in range(width):
        for j in range(height):
            n3[i,j] = mandelbrot(r1[i] + 1j*r2[j],maxiter)
    return (r1,r2,n3)

import sys
for cmap in sys.argv[1:]:
    file = f'numba-plot-{cmap}.png'
    _,_,n3 = mandelbrot_set(-1.5,1.5,-1.2,1.2,800,600,100)
    plt.imsave(file, n3.T, cmap= cm.get_cmap(cmap,10000))