[Numpy-discussion] SVD error in Numpy. NumPy Update reversed?

Matthieu Brucher matthieu.brucher at gmail.com
Mon Mar 24 11:50:30 EDT 2008


It was added as a compile-time #define on the SVN some days ago ;)

Matthieu

2008/3/24, Zachary Pincus <zachary.pincus at yale.edu>:
>
> Hi all,
>
>
> > I looked at line 21902  of dlapack_lite.c, it is,
> >
> >        for (niter = iter; niter <= 20; ++niter) {
> >
> > Indeed the upper limit for iterations in the
> > linalg.svd code is set for 20.  For now I will go with
> > my method (on earlier post) of squaring the matrix and
> > then doing svd when the original try on the original
> > matrix throws the linalg.linalg.LinAlgError.  I do not
> > claim that this is a cure-all.  But it seems to work
> > fast and avoids the original code from thrashing
> > around in a long iteration.
> >
> > I would suggest this be made explicit in the NumPy
> > documentation and then the user be given the option to
> > reset the limit on the number of iterations.
> >
> > Well, it certainly shouldn't be hardwired in as 20. At minimum it
> > should be a #define, and ideally it should be passed in with the
> > function call, but I don't know if the interface allows that.
>
>
> I just wanted to mention that this particular issue has bitten me in
> the past too. It would be nice to be able to have a bit more control
> over the SVD iteration limit either at compile-time, or run-time.
>
> Zach
>
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-- 
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