dolfin team mailing list archive

["Johan Hoffman" <jhoffman@xxxxxxxxxx>]

> I just realized that there is a nice way to simplify the definition of
> Functions and BoundaryConditions. The typical way to create a Function
> (and similarly for BoundaryCondition) is to make a subclass of
> Function and then create an object of that class:
>
>   class MyFunction : public Function
>   {
>     real eval(const Point& p, unsigned int i)
>     {
>       return p.x * sin(p.y);
>     }
>   };
>
>   MyFunction f;
>
> A simpler way to do this is to create an anonymous class and directly
> initialize the Function. That way, you save a line of code and you
> don't have to come up with a name for the class:
>
>   class : public Function
>   {
>     real eval(const Point& p, unsigned int i)
>     {
>       return p.x * sin(p.y);
>     }
>   } f;
>
> Also note that you can do this inside functions and other classes, so
> it's straightforward to create a new Function anywhere in the
> code. See new convection-diffusion demo for an illustration.
>
> Nice.

Very nice.

/Johan