Thank you Daniel for the clear quick answer. I will follow it. Best, Najwa
On Wednesday, July 19, 2023 at 5:16:14 PM UTC+3 [email protected] wrote: > Najwa, > > The documentation of VectorTools::integrate_difference( > https://www.dealii.org/current/doxygen/deal.II/namespaceVectorTools.html#a676190d2c897ac5da68a9c460fa95832) > > says > > > The additional argument weight allows to evaluate weighted norms. The > weight function may be scalar, establishing a spatially variable weight in > the domain for all components equally. This may be used, for instance, to > only integrate over parts of the domain. The weight function may also be > vector-valued, with as many components as the finite element: Then, > different components get different weights. A typical application is when > the error with respect to only one or a subset of the solution variables is > to be computed, in which case the other components would have weight values > equal to zero. The ComponentSelectFunction > <https://www.dealii.org/current/doxygen/deal.II/classComponentSelectFunction.html> > > class is particularly useful for this purpose as it provides such a "mask" > weight. The weight function is expected to be positive, but negative values > are not filtered. The default value of this function, a null pointer, is > interpreted as "no weighting function", i.e., weight=1 in the whole domain > for all vector components uniformly. > > Best, > Daniel > > On Wed, Jul 19, 2023 at 8:01 AM Najwa Alshehri <[email protected]> > wrote: > >> Dear group members, >> >> I have one question, >> >> I am trying to calculate the L2 norm of the error of a solution. In >> particular, I have a *vector of the solution* u_omega and a *FeSystem* >> with two fes. >> >> I am interested in computing the L2 norm of the error related to the >> first fe using *integrate_difference * function. (Note here u_omega is *not >> a blocked vector*, however, it has two solutions stacked together in one >> vector). Can I extract the solution of the first part from u_omega? >> >> >> >> Thank you in advance for your help. >> >> Best, >> >> Najwa >> >> -- >> The deal.II project is located at http://www.dealii.org/ >> For mailing list/forum options, see >> https://groups.google.com/d/forum/dealii?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "deal.II User Group" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/dealii/9741338e-2a31-418b-815d-277a5d7cb573n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/dealii/9741338e-2a31-418b-815d-277a5d7cb573n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/3a92adbb-f16d-4ac2-89d7-3ffac4a9bf5fn%40googlegroups.com.
