Jaroslav Hajek wrote: > On Fri, May 14, 2010 at 9:15 AM, Carlo de Falco <carlo.defa...@gmail.com> > wrote: >> On 13 May 2010, at 23:00, Lukas Reichlin wrote: >> >>>> Certainly. But at this event, only Windows machines were available >>>> and >>>> Matlab was already pre-installed. I had little options >>>> about the setup. (and i do not want to say it loud, but M is still >>>> faster, [1]. Admittingly, Octave has improved since 2006, and I see >>>> only >>>> difference by a factor of 2-3 instead of 4-5). >>>> >>>> [1] http://arxiv.org/abs/cs/0603001v1 >> Do you still have the code to run those benchmarks at hand? >> It would be very interesting to compare how the speed of Octave >> changed between version 2.9.4 and 3.3, >> for a fair comparison you would need to run the tests on the same >> hardware though.. >> c. >> > > > Checking the BioSig code, I even found snippets such as: > > % Instantaneous heart period hp > for k=2:length(t) > hp(k)=(t(k)-t(k-1)); > end > hp(1)=NaN; > hp_mean=mean(hp) > > and hp is not even preallocated. Of course, code like this has no > chance to be efficient in Octave. > Another example snippet of extremely poorly vectorized code is > > j=1; > n_all=ones(1,length(ke_all)); %number of consecutive ectopic beats > while j<length(ke_all) > while ((j<=length(ke_all)-1)&((ke_all(j+1)-ke_all(j))==1)) > ke_all(j)=[]; %deletion of consecutive indices > n_all(j)=n_all(j)+1; > end; > j=j+1; > end; > n_all(length(ke_all)+1:end)=[]; > > not only there is a double loop, there is also a vector operation > (element deletion) in the inner loop. > I would expect, however, that this is sluggish in Matlab as well, no > JIT can probably handle this. >
What is your point here ? Some people are not as good in coding as others, the function this student wrote is still useful. What does it say about the performance of Octave vs. M ? Zero, Nil, Nothing. BTW, this function is not part of the biosig benchmark. Alois ------------------------------------------------------------------------------ _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
