mandelbrot-cosine

#!/usr/bin/env python3

from tkinter import Tk, Label, PhotoImage
from math import log, pi
from cmath import cos

w, h = 1200, 960
root = Tk()
label = Label(root)
label.pack()
img = PhotoImage(width=w,height=h)
label.config(image=img)
root.wait_visibility()
xc, yc = - 0.35, 0.005
mag = 0.9
imax, zmax = 100, 100

for y in range(h):
    hexdata = ""
    for x in range(w):
        c = complex(xc + (2*x - w) / (w*mag), -yc - (2*y - h) / (w*mag))
        z = complex(0.0, 0.0)
        backgnd = 0
        for i in range(imax):
            z =   c + pi * cos(z)
            if abs(z.imag) >= zmax:
                backgnd = log(i - log(log(abs(z.imag)),20)) / 3.0
                break
        v = max(0.0, 1.0 - abs(1.0 - backgnd))
        blue = (v ** 4, v ** 2.5, v)
        sepia = (v, v ** 1.5, v ** 3)
        color = blue if backgnd <=1 else sepia
        hexdata += '#%02X%02X%02X ' % tuple(int(n * 255) for n in color)
    img.put('{' + hexdata + '}', to=(0,y))
    root.update()

root.mainloop()