To clarify: if you really need the solution at an *arbitrary* point,
you will want to use MeshFunction, initialized with either the
System's solution vector or with a localized serial copy of that
vector. See exact_error_estimator.C for an example.
99% of the time, though, you already know that you want the solution
on a particular local element (or better yet, on a quadrature point on
that local element), and then it's much more efficient to do what John
suggests. See ex13 for an example.

Roy
On Wed, 11 Jul 2007, John Peterson wrote:
> Once you figure out which element the point is in, reinitialize
> the finite element object at that point. (See the FE::reinit()
> which takes a pointer to a vector of points.) This will recompute
> the shape function values at that point, which will allow you to
> loop over them and obtain the value as
>
> u(x) = sum_i u_i phi_i(x)
>
> J
>
>
> pcorreia@... writes:
> > How can I, after finding the solution, obtain its value at an arbitrary
> > point? For this I think is needed interpolation via MeshFunction but how
> > to implement it?
> > Thanks
> > /Paulo
>
> 
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C  the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Libmeshusers mailing list
> Libmeshusers@...
> https://lists.sourceforge.net/lists/listinfo/libmeshusers
>
