On 9/14/11 1:01 PM, Christopher Barker wrote:
numpy.ndarray.resize is a different method, and I'm pretty sure it should be as fast or faster that np.empty + np.append.
My profile:
In [25]: %timeit f1 # numpy.resize() 10000000 loops, best of 3: 163 ns per loop
In [26]: %timeit f2 #numpy.ndarray.resize() 10000000 loops, best of 3: 136 ns per loop
In [27]: %timeit f3 # numpy.empty() + append() 10000000 loops, best of 3: 136 ns per loop
those last two couldn't b more identical!
(though this is an excercise in unrequired optimization!)
My test code:
#!/usr/bin/env python
""" test_resize
A test of various numpy re-sizing options
"""
import numpy
def f1(): """ numpy.resize """
l = 100 a = numpy.zeros((l,)) for i in xrange(1000): l += l a = numpy.resize(a, (l,) )
return None
def f2(): """ numpy.ndarray.resize """
l = 100 a = numpy.zeros((l,)) for i in xrange(1000): l += l a.resize(a, (l,) )
return None
def f3(): """ numpy.empty + append """
l = 100 a = numpy.zeros((l,)) for i in xrange(1000): b = np.empty((l,)) a.append(b)
return None