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

[Joshua Redstone]

Another data point: for kicks, I also tried running the Octave 2.9.18
release from sourceforge, running it directly from the .dmg (i.e., without
installing),
and I got the same kind of numerical error.
Josh

On Sat, Apr 5, 2008 at 10:06 AM, Joshua Redstone <redstone at gmail.com> wrote:

> It's encouraging you're getting reasonable numbers on the example I sent -
> hopefully I can too!
> On the question you asked, I get:
>   octave-3.0.0:10> zzz=randn(1000); max(max(zzz*inv(zzz)))
>   ans =  1.0000
>
> Re libraries - any suggestions how to find which one may be broken?  I
> installed Octave with the stock
> osx binary package from http://octave.sourceforge.net/.  If the cause is
> broken libraries, would they have had to come from
> that release?
> I'm trying to compile octave from source code so I can put a bunch of
> printfs in __qp__(), but am getting some make errors about shell options.
> Thanks,
> Josh
>
>
> On Fri, Apr 4, 2008 at 11:06 PM, Dmitri A. Sergatskov <
> dasergatskov at gmail.com> wrote:
>
> > On Fri, Apr 4, 2008 at 8:24 PM, Joshua Redstone <redstone at gmail.com>
> > wrote:
> > > Hi John,
> > > I've attached a data file created with (on OSX):
> > >     save -binary -z "./example.dat" x0 H Q A B LB UB A_LB A_IN A_UB
> > >
> > > The following should reproduce the problem for you:
> > >    load "example.dat"
> > >    [X, OBJ, INFO, LAMBDA] = qp(x0, H, Q, A, B, LB, UB, A_LB, A_IN,
> > A_UB)
> > >
> > > With my qp.m that I modified so the last arguement is maxiter, I get
> > the
> > > follow first few lines of output:
> > > octave-3.0.0:5> [X, OBJ, INFO, LAMBDA] = qp(x0, H, Q, A, B, LB, UB,
> > A_LB,
> > > A_IN, A_UB, 187)
> > >  X =
> > >
> > >    0.17954
> > >     0.00000
> > >    0.01742
> > >     0.00304
> > >    0.16220
> > >     [... output truncated.... ]
> >
> > I cannot reproduce the problem you were describing:
> >
> > octave:11> X
> > X =
> >
> >   1.8652e-01
> >  -1.6807e-18
> >   1.1024e-02
> >   2.4571e-03
> >   1.5873e-01
> >   4.5925e-18
> >   3.0011e-17
> > ....
> >
> > octave:12> max(X)
> > ans =  0.18652
> >
> >   2.2584e-18
> > octave:13> sum(X)
> > ans =  1.00000
> >
> > I suspect that some of your library is broken.
> > (BLAS/LAPACK is a popular candidate.)
> > Just for kicks what do you get for:
> >
> > zzz=randn(1000); max(max(zzz*inv(zzz)))
> >
> > ?
> >
> > Sincerely,
> >
> > Dmitri.
> > --
> >
>
>
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