BUG: Fix average_of_best in loop_timer

quantecon/util/tests/test_timing.py

@@ -6,7 +6,7 @@
 
 import time
 from numpy.testing import assert_allclose
-from nose.tools import eq_
+from nose.tools import eq_, ok_
 from quantecon.util import tic, tac, toc, loop_timer
 
 
@@ -48,6 +48,9 @@ def test_function_two_arg(n, a):
         for tm in test_two_arg:
             assert(abs(tm - self.h) < 0.01)
 
+        for (average_time, average_of_best) in [test_one_arg, test_two_arg]:
+            ok_(average_time >= average_of_best)
+
 
 if __name__ == '__main__':
     import sys

quantecon/util/timing.py

@@ -9,6 +9,7 @@
 
 """
 import time
+import numpy as np
 
 
 class __Timer__:
@@ -143,15 +144,15 @@ def loop_timer(self, n, function, args=None, verbose=True, digits=2,
 
         """
         tic()
-        all_times = []
+        all_times = np.empty(n)
         for run in range(n):
             if hasattr(args, '__iter__'):
                 function(*args)
             elif args is None:
                 function()
             else:
                 function(args)
-            all_times.append(tac(verbose=False, digits=digits))
+            all_times[run] = tac(verbose=False, digits=digits)
 
         elapsed = toc(verbose=False, digits=digits)
 
@@ -161,10 +162,8 @@ def loop_timer(self, n, function, args=None, verbose=True, digits=2,
         print("Total run time: %d:%02d:%0d.%0*d" %
               (h, m, s, digits, (s % 1)*(10**digits)))
 
-        average_time = sum(all_times) / len(all_times)
-
-        best_times = all_times[:best_of]
-        average_of_best = sum(best_times) / len(best_times)
+        average_time = all_times.mean()
+        average_of_best = np.sort(all_times)[:best_of].mean()
 
         if verbose:
             m, s = divmod(average_time, 60)