Re: [OctDev] randn() broken

[David B. <Dav...@mo...>]

I was using gcc 3.3.1 and didn't see the problem. I'm now using 3.4.1
and also don't see the problem... If it is a problem with gcc, then
a simplier piece of code than randn that demonstrates the problem would
be needed.

However, as it seems to be fixed the alternative is to check the resolved
bugs in gcc between 3.3.1 and 3.4.1 and see if there is anything that mig=
ht
relate (big task). Alternatively, just ignore the problem and get JWE to
bump the recommended version of gcc to compile octave upto gcc 3.4.x

Regards
David

According to Justus Piater <Jus...@UL...> (on 01/12/05):
> I have some more news:
>=20
> It seems that compiling octave-forge-2004.09.09/FIXES/rand.cc (and
> perhaps later versions) using gcc 3.3.x produces a dysfunctional
> randn(). Older and newer compilers seem to work fine.
>=20
> Is this compatible with our experience out there?
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> Specifically:
> - My faulty setup was compiled using gcc 3.3.2 (i686).
> - Simply recompiling rand.cc using gcc 3.4.1 produced a correct randn().
> - Another user reported similar problems with gcc 3.3.3 and gcc 3.3.5.
> - The same user reported a working version with gcc 3.2.2.
>=20
>=20
> Since the thread is already more than two months old, here's a
> reminder of the problem.
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> Output (faulty) of the following sequence of commands is available at
> http://www.montefiore.ulg.ac.be/~piater/Demos/randn-dots.eps[.gz]:
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> octave> randn("seed", 12345);
> octave> plot(1:10000, randn(1, 10000), ".");
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> The figure demonstrates that the samples are nowhere near Gaussian for
> sample sizes of at least up to several thousands, due to a strange
> sequential clustering effect.
>=20
> --=20
> Justus H. Piater, Ph.D.         http://www.montefiore.ulg.ac.be/~piater=
/
> Institut Montefiore, B28        Phone: +32-4-366-2279
> Universit=E9 de Li=E8ge, Belgium    Fax:   +32-4-366-2620
>=20
>=20
>=20
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--=20
David Bateman                                Dav...@mo...
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