[SciPy-User] optimize.fmin_cg terminates when w - grad*1e-10 yields lower obj & grad
Mon Oct 5 15:55:38 CDT 2009
Looks like optimize.zoom() is also buggy in that it will return a step size
corresponding to an increased objective if it can't find a step in maxiter
On Mon, Oct 5, 2009 at 4:33 PM, <email@example.com> wrote:
> On Mon, Oct 5, 2009 at 4:11 PM, Jason Rennie <firstname.lastname@example.org> wrote:
> > The bug seems to be that scipy.optimize.linesearch.line_search can return
> > step size which increases the objective. Later linesearches are then
> > fubar'd b/c the (phi0-old_old_fval)/derphi0 calculation yields a negative
> > value.
> > Would someone mind sanity-checking this assertion? Is it possible
> > for minpack2.dcsrch to return a step which yields a negative objective?
> > seeing it when the amin value is hit. I.e. it's returning a step size of
> > 1e-8.
> > Thanks,
> > Jason
> bug candidate: linesearch doesn't honor warn
> Has fortran 0 or 1 based indexing?
> I think task[1:4] == 'WARN':
> should instead be
> task[:4] == 'WARN':
> > --
> > Jason Rennie
> > Research Scientist, ITA Software
> > 617-714-2645
> > http://www.itasoftware.com/
> > _______________________________________________
> > SciPy-User mailing list
> > SciPy-User@scipy.org
> > http://mail.scipy.org/mailman/listinfo/scipy-user
> SciPy-User mailing list
Research Scientist, ITA Software
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