"""
An example showing the Julia set displayed as a z-warped surface.

The Julia set is a fractal (see http://en.wikipedia.org/wiki/Julia_set
). We display it here in a canyon-like view using mlab's surf function:
:func:`enthought.mayavi.mlab.surf`.
"""

# Author: Gael Varoquaux <gael.varoquaux@normalesup.org> 
# Copyright (c) 2008, Enthought, Inc.
# License: BSD Style.


from enthought.mayavi import mlab
import numpy as np

# Calculate the Julia set on a grid
x, y = np.ogrid[-1.5:0.5:500j, -1:1:500j]
z = x + 1j*y

julia = np.zeros(z.shape)

for i in range(50):
    z = z**2 -0.70176 -0.3842j
    julia += 1/float(2+i)*(z*np.conj(z) > 4)

# Display it
mlab.figure(size=(400, 300))
mlab.surf(julia, colormap='gist_earth', warp_scale='auto', vmax=1.5)

# A view into the "Canyon"
mlab.view(65, 27, 322, [ 30.,  -13.7,  136])
mlab.show()