Speed-up for loops

Michael Kreim michael at perfect-kreim.de
Thu Sep 2 12:02:40 CEST 2010


I was comparing the speed of a simple loop program between Matlab and 

My Codes:
$ cat addition.py
imax = 1000000000
a = 0
for i in xrange(imax):
     a = a + 10
print a

$ cat addition.m
imax = 1e9;
a = 0;
for i=0:imax-1
     a = a + 10;

The results look like this:
$ /usr/bin/time --verbose python addition.py
         Command being timed: "python addition.py"
         User time (seconds): 107.30
         System time (seconds): 0.08
         Percent of CPU this job got: 97%
         Elapsed (wall clock) time (h:mm:ss or m:ss): 1:50.09

$ /usr/bin/time --verbose matlab -nodesktop -nosplash -r "addition"
         Command being timed: "matlab -nodesktop -nosplash -r addition"
         User time (seconds): 7.65
         System time (seconds): 0.18
         Percent of CPU this job got: 94%
         Elapsed (wall clock) time (h:mm:ss or m:ss): 0:08.25

Unfortunately my Python Code was much slower and I do not understand why.

Are there any ways to speed up the for/xrange loop?
Or do I have to live with the fact that Matlab beats Python in this example?

Thanks a lot for your answers.

With best regards,


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