polypoly.py

'''
Code snippet to plot multiple triangle's in Matplotlib using different methods.
'''
import time
import sys
import matplotlib.pyplot as pp
import numpy as np
from matplotlib.collections import PolyCollection
import random
 
if sys.platform == "win32":
     # On Windows, the best timer is time.clock()
     default_timer = time.clock
else:    
    # On most other platforms the best timer is time.time()    
    default_timer = time.time
     
     
# generate ends for the triangle line segments
xtris = []
ytris = []
verts = []
#verts_np = []
for i in range(1000):
    x1 = random.random()
    x2 = x1 + random.random()/5.0
    x3 = x1 + random.random()/5.0
    xtips = [x1,x2,x3]
    y1 = random.random()
    y2 = y1 + random.random()/5.0
    y3 = y1 + random.random()/5.0
    ytips = [y1,y2,y3]
    xtris.append(xtips)
    ytris.append(ytips)
    tri = ((x1,y1),(x2,y2),(x3,y3))
    verts.append(tri)
#    tri_np = np.array(tri)
#    verts_np.append(tri_np)
verts_np = np.array(verts)
 
############################
# time sequential call to matplotlib
pp.figure()
pp.subplot(1,5,1)
 
t0 = default_timer()
for xtips,ytips in zip(xtris,ytris):
    pp.fill(xtips,ytips,
            facecolor='b',alpha=0.1, edgecolor='none')
t1 = default_timer()
 
pp.title('Sequential Plotting')
 
print 'Execution time for sequential plotting = %f sec' % (t1-t0)
 
# rebuild ends using none to separate polygons
xlist = []
ylist = []
for xtips,ytips in zip(xtris,ytris):
    xlist.extend(xtips)
    xlist.append(None)
    ylist.extend(ytips)
    ylist.append(None)
 
############################
# build argument list
call_list = []
for xtips,ytips in zip(xtris,ytris):
    call_list.append(xtips)
    call_list.append(ytips)
    call_list.append('-b')
     
############################
# time single call to matplotlib
pp.subplot(1,5,2)
 
t0 = default_timer()
pp.fill(*call_list,
            facecolor='b',alpha=0.1, edgecolor='none')
 
t1 = default_timer()
 
pp.title('Single Plot extended call')
 
print 'Execution time for extended call plotting = %f sec' % (t1-t0)
 
     
############################
# time single call to matplotlib
pp.subplot(1,5,3)
 
t0 = default_timer()
pp.fill(xlist,ylist,
        facecolor='b',alpha=0.1,edgecolor='none')
t1 = default_timer()
 
pp.title('Single Plot Using None')
 
print 'Execution time when using None = %f sec' % (t1-t0)


#############################
# time single call to matplotlib using PolyCollection & list of point list
ax = pp.subplot(1,5,4)

t0 = default_timer()
pcoll = PolyCollection(verts, closed=True, 
                       facecolor='b', alpha=0.1, edgecolor='none')
ax.add_collection(pcoll, autolim=True)
pp.autoscale()
t1 = default_timer()

pp.title('Using Polycollection\nwith list of point tuples')

print 'Execution time when using PolyColl + list of lists = %f sec' % (t1-t0)


#############################
# time single call to matplotlib using PolyCollection & numpy array
ax = pp.subplot(1,5,5)

t0 = default_timer()
pcoll_np = PolyCollection(verts_np, closed=True, 
                          facecolor='b', alpha=0.1, edgecolor='none')
ax.add_collection(pcoll_np, autolim=True)
pp.autoscale()
t1 = default_timer()

pp.title('Using Polycollection\nwith numpy array')

print 'Execution time when using PolyColl + np array = %f sec' % (t1-t0)

pp.show()