bgneal@47: """ Code example from Complexity and Computation, a book about
bgneal@47: exploring complexity science with Python.  Available free from
bgneal@47: 
bgneal@47: http://greenteapress.com/complexity
bgneal@47: 
bgneal@47: Copyright 2011 Allen B. Downey.
bgneal@47: Distributed under the GNU General Public License at gnu.org/licenses/gpl.html.
bgneal@47: 
bgneal@47: Modified by Brian Neal to add a variable delay to the animation and to provide
bgneal@47: the cval parameter to convolve.
bgneal@47: 
bgneal@47: """
bgneal@47: 
bgneal@47: import numpy
bgneal@47: import scipy.ndimage
bgneal@47: 
bgneal@47: import matplotlib
bgneal@47: matplotlib.use('TkAgg')
bgneal@47: import matplotlib.pyplot as pyplot
bgneal@47: 
bgneal@47: 
bgneal@47: class Life(object):
bgneal@47:     """Implements Conway's Game of Life.
bgneal@47: 
bgneal@47:     n:     the number of rows and columns
bgneal@47:     """
bgneal@47: 
bgneal@47:     def __init__(self, n, mode='wrap', cval=0.0, random=False):
bgneal@47:         """Attributes:
bgneal@47:         n:      number of rows and columns
bgneal@47:         mode:   how border conditions are handled
bgneal@47:         array:  the numpy array that contains the data.
bgneal@47:         weights: the kernel used for convolution
bgneal@47:         """
bgneal@47:         self.n = n
bgneal@47:         self.mode = mode
bgneal@47:         self.cval = cval
bgneal@47:         if random:
bgneal@47:             self.array = numpy.random.random_integers(0, 1, (n, n))
bgneal@47:         else:
bgneal@47:             self.array = numpy.zeros((n, n), numpy.int8)
bgneal@47: 
bgneal@47:         self.weights = numpy.array([[1,1,1],
bgneal@47:                                     [1,10,1],
bgneal@47:                                     [1,1,1]])
bgneal@47: 
bgneal@47:     def add_glider(self, x=0, y=0):
bgneal@47:         coords = [(0,1), (1,2), (2,0), (2,1), (2,2)]
bgneal@47:         for i, j in coords:
bgneal@47:             self.array[x+i, y+j] = 1
bgneal@47: 
bgneal@47:     def loop(self, steps=1):
bgneal@47:         """Executes the given number of time steps."""
bgneal@47:         [self.step() for i in xrange(steps)]
bgneal@47: 
bgneal@47:     def step(self):
bgneal@47:         """Executes one time step."""
bgneal@47:         con = scipy.ndimage.filters.convolve(self.array,
bgneal@47:                                              self.weights,
bgneal@47:                                              mode=self.mode,
bgneal@47:                                              cval=self.cval)
bgneal@47: 
bgneal@47:         boolean = (con==3) | (con==12) | (con==13)
bgneal@47:         self.array = numpy.int8(boolean)
bgneal@47: 
bgneal@47: 
bgneal@47: class LifeViewer(object):
bgneal@47:     """Generates an animated view of the grid."""
bgneal@47:     def __init__(self, life, cmap=matplotlib.cm.gray_r, delay=1000):
bgneal@47:         self.life = life
bgneal@47:         self.cmap = cmap
bgneal@47:         self.delay = delay
bgneal@47: 
bgneal@47:         self.fig = pyplot.figure()
bgneal@47:         pyplot.axis([0, life.n, 0, life.n])
bgneal@47:         pyplot.xticks([])
bgneal@47:         pyplot.yticks([])
bgneal@47: 
bgneal@47:         self.pcolor = None
bgneal@47:         self.update()
bgneal@47: 
bgneal@47:     def update(self):
bgneal@47:         """Updates the display with the state of the grid."""
bgneal@47:         if self.pcolor:
bgneal@47:             self.pcolor.remove()
bgneal@47: 
bgneal@47:         a = self.life.array
bgneal@47:         self.pcolor = pyplot.pcolor(a, cmap=self.cmap)
bgneal@47:         self.fig.canvas.draw()
bgneal@47: 
bgneal@47:     def animate(self, steps=10):
bgneal@47:         """Creates the GUI and then invokes animate_callback.
bgneal@47: 
bgneal@47:         Generates an animation with the given number of steps.
bgneal@47:         """
bgneal@47:         self.steps = steps
bgneal@47:         self.fig.canvas.manager.window.after(self.delay, self.animate_callback)
bgneal@47:         pyplot.show()
bgneal@47: 
bgneal@47:     def animate_callback(self):
bgneal@47:         """Runs the animation."""
bgneal@47:         for i in range(self.steps):
bgneal@47:             self.life.step()
bgneal@47:             self.update()
bgneal@47: 
bgneal@47: 
bgneal@47: def main(script, n=20, *args):
bgneal@47: 
bgneal@47:     n = int(n)
bgneal@47: 
bgneal@47:     life = Life(n, random=False)
bgneal@47:     life.add_glider()
bgneal@47:     viewer = LifeViewer(life)
bgneal@47:     viewer.animate(steps=100)
bgneal@47: 
bgneal@47: 
bgneal@47: if __name__ == '__main__':
bgneal@47:     import sys
bgneal@47: 
bgneal@47:     profile = False
bgneal@47:     if profile:
bgneal@47:         import cProfile
bgneal@47:         cProfile.run('main(*sys.argv)')
bgneal@47:     else:
bgneal@47:         main(*sys.argv)