[Dune] Multilinear geometry local(global) method bug?

Martin Nolte nolte at mathematik.uni-freiburg.de
Fri Sep 12 13:38:38 CEST 2014


Hi Aleksejs,

yes, that is intentional. It simplifies the definition of tolerance to a small 
multiple of the machine epsilon. Otherwise you would have to define tolerance like

const double tolerance = std::sqrt( 10*std::numeric_limits< double >::epsilon() );

In fact, the above line is even incorrect, as std::sqrt is not a constexpr. It 
also prohibits round-off errors.

Best,

Martin


On 09/12/2014 10:34 AM, Aleksejs Fomins wrote:
> Dear Dune,
>
> In the Multilinear Geometry class method local(global) currently
> implements Newton's method. The current termination condition for the
> method is
>
> while( dx.two_norm2() > tolerance );
>
> Which means that currently the square of the estimated quadratic error
> of local coordinate is compared with the error tolerance. Is this
> intentional?
>
> Regards,
> Aleksejs
>
>
>
> _______________________________________________
> Dune mailing list
> Dune at dune-project.org
> http://lists.dune-project.org/mailman/listinfo/dune
>

-- 
Dr. Martin Nolte <nolte at mathematik.uni-freiburg.de>

Universität Freiburg                                   phone: +49-761-203-5630
Abteilung für angewandte Mathematik                    fax:   +49-761-203-5632
Hermann-Herder-Straße 10
79104 Freiburg, Germany




More information about the Dune mailing list