Re: octave benchmark test

[Paul Kienzle]

On Mar 8, 2004, at 7:17 PM, Dmitri A. Sergatskov wrote:

> Paul Kienzle wrote:
>
> > It is reported to have better performance on partially ordered lists,
> > but worse on random data compared to matlab.
>
> Well, may be I misunderstood what does "partially ordered means", but 
> here is
> what I got.

Thanks.  I don't know the details of the algorithm, but I believe it is
a merge sort variant.    These tend to do better if you start with a
small number of long 'runs' rather than a large number of short
'runs', as in the following:

octave:42> w=[1:1000000];
octave:43> x=repmat([1:500000],1,2);
octave:44> y=repmat([1:100000],1,10);
octave:45> z=rand(1000000,1);
octave:46> tic; sort(w); toc
ans = 0.60063
octave:47> tic; sort(x); toc
ans = 0.80005
octave:48> tic; sort(y); toc
ans = 1.0342
octave:49> tic; sort(z); toc
ans = 1.4839

x is an imporant case for table lookups.

It would be nice if the random case were
1x rather 1.5x matlab.  Still,  1.5x is loads
better than the 7x it used to be.

Paul Kienzle
address@hidden



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