qp() in Octave 3.0.0 returns result egregiously violating input constraints

[Joshua Redstone]

I'm sorry I don't have an instance of the problem on a smaller data set.
RE debugging - I think it's good news it fails with such outrageous values
and that the first element of X is one such value.  If I could get octave to
build on my mac,  I'd be tempted to put temporary checks in the __qp__()
routine that fail if there are any intermediate values greater than 1e+10.
Hopefully that would narrow it down a bit.
I may have some time to play with this a bit this weekend.
Josh

On Sat, Apr 5, 2008 at 3:17 PM, Ben Abbott <bpabbott at mac.com> wrote:

>
> On Apr 5, 2008, at 5:58 PM, Thomas Treichl wrote:
>
> > Ben Abbott schrieb:
> >
> > > I've built octave using Apple's lapack/blas (i.e. vecLib), so the
> > > problem isn't directly related to the lapack/blas, correct?
> > >
> >
> > True. Then what about the difference between your PPC and our IAs? Just
> > an idea...
> >
>
> I get exactly the same solution on my PPC (G4) using a build from Feb 5.
>
>
> >  However, when I tried the release-3-0-x branch which I build yesterday
> > > (and passed all tests), it fails (also built with vecLib).
> > > octave:8> result = 0.5*X'*H*X + X'*Q
> > > result =  5.4445e+58
> > > octave:9> tol = 10*eps;
> > > octave:10> all ( X > LB-tol & X < UB+tol)
> > > ans = 0
> > > octave:11> all ( A_LB-tol < A_IN*X & A_UB+tol > A_IN*X)
> > > ans = 0
> > >
> >
> > Hhhmmm...
> >
> >  Thomas, when did you build last? The sources for one I'm running were
> > > pulled from John's archive archive 2-3 days ago.
> > >
> >
> > I've just pulled a new snapshot from John's repository and rebuilt
> > everything. The same qr() results than before. However, somehow I think I
> > still don't know what's going on. Is it possible to reduce that kind of
> > problem to a much easier exercise (that also looks like a fail)?
> >
>
> I agree this would make isolating the problem easier.  As I have not
> studied qr() I don't know if I can be successful ... but I'll kill a bit of
> time on it this weekend. If I'm successful I'll post to post immediately.
>
> Ben
>
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