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

[Ben Abbott]

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