theano_vs_numpy.py

#!/usr/bin/env python

import numpy
import theano
import time

def timer(func):
  def wrapper(*args, **kwargs):
    print("Executing func %s" % func.__name__)
    start = time.time()
    func(*args, **kwargs)
    end = time.time()
    print("Elapsed time for func %s = %.2fs" % (func.__name__, end - start))
  return wrapper

@timer
def theano_cube(a):
  '''
  Cube a matrix using theano
  '''
  x = theano.tensor.matrix()
  y = pow(x, 3)
  f = theano.function([x], y)
  print(f(a))

@timer
def numpy_cube(a):
  '''
  Cube a matrix using theano
  '''
  print(numpy.power(a, 3)) 

@timer
def theano_eqn(a):
  '''
  Theano should canonicalize the equation y = x^3 / x^2 into y = x.
  '''
  x = theano.tensor.matrix()
  y = pow(x, 3) / (x * x)
  f = theano.function([x], y)
  print(f(a))

@timer
def numpy_eqn(a):
  '''
  Numpy doesn't optimize the equation y = x^3 / x^2.
  '''
  print(numpy.power(a, 3) / (a * a)) 

if __name__ == '__main__':
  a = numpy.random.rand(20000, 20000)
  theano_cube(a)
  numpy_cube(a)
  theano_eqn(a)
  numpy_eqn(a)