Re: [OctDev] Help making padarray.m quicker

[Per P. <per...@ma...>]

On Aug 11, 2004, at 04:12, Paul Kienzle wrote:

>
> On Aug 10, 2004, at 6:18 PM, Josep Mon=E9s i Teixidor wrote:
>
>> I've left padding with scalar values as it was in the second version
>> because, although in my intel box that was slower, as Paul sent
>> yesterday, that probably makes a real difference on MacOs X.
>
> Note the difference in version number: 2.1.55 for OS X,
> 2.1.57 for linux!  Octave may have changed to make the
> two more similar.  Does somebody have both versions
> available on the same system that they can compare?

FWIW, on a 1.25MHz G4 w 512MB RAM iMac with octave 2.1.57 I get (+/- =20
20% accuracy)

octave:1> n=3D800; A=3Dones(n,n);
octave:2> tic; B=3Dzeros(n+100,n+100); B(51:n+50,51:n+50)=3DA; toc
ans =3D 0.16152
octave:3> tic; =20
B=3Dcat(2,zeros(n+100,50),cat(1,zeros(50,n),A,zeros(50,n)),zeros(n+100,50)=
=20
); toc
ans =3D 0.19956

I don't have any pre-2.1.57 installs, but I'm pretty sure there weren't =20=

any changes between 2.1.55 and 2.1.57 that could justify the 10x diff =20=

in speed. Did you run the test on a memory starved (which for OS X =20
means <=3D256 MB) system?


/Per
--------
Per Persson, Ph.D. Applied Signal Processing
Resume, contact info and more:
http://homepage.mac.com/persquare