#!/usr/bin/env python

# 2017-02-12 Simple Mandelbrot / Julia set example
# http://algoristo.com/teaching/

import numpy as np

nsteps = 500

maxiter = 100

limit = 2.0

# Floats
xmin = -2.0
xmax = 1.0
ymin = -1.5
ymax = 1.5

# Julia set only
c = np.complex(0, 1)

datfile = open("heatmap.dat", "w")

for i in range(nsteps + 1):
    for j in range(nsteps + 1):
        x = xmin + i*(xmax - xmin)/nsteps
        y = ymin + j*(ymax - ymin)/nsteps

        # Julia
        #z = np.complex(x, y)
        
        # Mandelbrot
        c = np.complex(x, y)
        z = np.complex(0)

        for n in range(maxiter):
            z = z*z + c

            if abs(z) > limit:
                break

        # Note: starting point x, y, not the result
        datfile.write("%f %f %f\n" % (x, y, n))

datfile.close()