In [2]:
# Math libraries
import numpy as np
from math import sqrt
# Matplotlib plotting libraries
import matplotlib.pyplot as plt
%matplotlib inline
# Bokeh plotting libraries
import bokeh.plotting as blt
blt.output_notebook()
In [3]:
class JuliaSet(object):
def __init__(self,c,n=100):
self.c = c
self.n = n
self._d = 0.001
self._complexplane = np.array([])
self.set = np.array([])
def juliamap(self,z):
return z**2 + self.c
def iterate(self,z):
m=0
while True:
z=self.juliamap(z)
m+=1
if abs(z)>2:
return m
if m>=self.n:
return 0
def set_spacing(self,d,k=-2,s=2):
self._d=d
self.k=k
self.s=s
r=np.arange(k,s,self._d)
x , y = np.meshgrid(r,r)
self._complexplane = x+y*1j
def generate(self):
iterate = np.vectorize(self.iterate)
self.set= iterate(self._complexplane)
return self.set
In [4]:
class JuliaSetPlot(JuliaSet):
"""Extend JuliaSet to add plotting functionality"""
def __init__(self, *args, **kwargs):
# Invoke constructor for JuliaSet first, unaltered
JuliaSet.__init__(self, *args, **kwargs)
# Add another attribute: a rendered image array
#self.img = np.array([])
def get_dim(self):
"""Return linear number of points in axis"""
return int(sqrt(self.set.size))
#def render(self):
# """Render image as square array of ints"""
# if not self.set.size: self.generate()
# # Convert inefficient list to efficient numpy array
# self.img = np.array(self.set)
# # Reshape array into a 2d complex plane
# dim = int(sqrt(len(self.img)))
# self.img = np.reshape(self.img, (dim,dim)).T
def show(self):
"""Use matplotlib to plot image as an efficient mesh"""
if not self.set.size: self.generate()
plt.figure(1, figsize=(12,9))
xy = np.linspace(self.k,self.s,self.get_dim())
plt.pcolormesh(xy, xy, self.set, cmap=plt.cm.hot)
plt.colorbar()
plt.show()
def interact(self):
"""Use bokeh to plot an interactive image"""
from matplotlib.colors import rgb2hex
if not self.set.size: self.generate()
# Mimic matplotlib "hot" color palette
colormap = plt.cm.get_cmap("hot")
bokehpalette = [rgb2hex(m) for m in colormap(np.arange(colormap.N))]
# Create bokeh figure
f = blt.figure(x_range=(self.k,self.s), y_range=(self.k,self.s), plot_width=600, plot_height=600)
f.image(image=[self.set], x=[self.k], y=[self.k], dw=[self.s-self.k], dh=[self.s-self.k], palette=bokehpalette, dilate=True)
blt.show(f)
In [5]:
j = JuliaSetPlot(1j)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()
In [6]:
j = JuliaSetPlot(2+1j)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()
In [7]:
j = JuliaSetPlot(-1+2j)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()
In [8]:
j = JuliaSetPlot(-1j)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()
In [9]:
j = JuliaSetPlot(1)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()
In [ ]:
j = JuliaSetPlot(-1)
%time j.set_spacing(0.006)
%time j.generate()
%time j.show()