ufl team mailing list archive

[Kent Andre <kent-and@xxxxxxxxx>]

On fr., 2009-01-02 at 09:42 +0100, Martin Sandve Alnæs wrote:
> On Thu, Jan 1, 2009 at 11:30 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
> >
> >
> > Martin Sandve Alnæs wrote:
> >>
> >> The wiki isn't quite updated, but go ahead. Or you can just send them
> >> here.
> >>
> >
> > It would be useful an integration scheme could be attached to integrals
> > (dx0, dx1, etc). This would make selective integration schemes simple to
> > implement.
> >
> > Garth
> 
> Ok, adding any kind of metadata to Integral poses no problems.
> How should it look? How general can we make it?
> 
> Currently you can do:
>   dx0 = dx(0)
> 
> We could add something like:
>   quad_order = 3
>   quad_rule = [
>     (1.0/3.0, (0.0, 0.0)),
>     (1.0/3.0, (1.0, 0.0))
>     (1.0/3.0, (0.0, 1.0))
>     ]
>   integration_scheme1 = IntegrationScheme(quad_order)
>   integration_scheme2 = IntegrationScheme(quad_rule)
> 
>   dx0 = dx(0, integration_scheme1)
>   dx1 = dx(1, integration_scheme2)
> 
>   a = u*v*dx0 + f*v*dx1
> 
> where quad_order is the minimum order of the quadrature
> scheme wanted. The default integration scheme is
> undefined (None) in which case the form compiler decides.
> IntegrationScheme can in principle be arbitrarily complex,
> even containing known quadrature rules.
> 
> Alternatively, we can skip the IntegrationScheme class:
>   dx0 = dx(0, 3)
>   dx1 = dx(0, quad_rule)

Very good! 

> 
> In the case of facet integrals, the points are defined
> on a single reference polygon.
> 
> How should we handle non-quadrature integration options?
> 

Don't bother. The compiler should bail out. It should 
correspond to a projection, but I think implementing 
it would smell more than it tastes. 


> (And using functions on quadrature elements in an
> integral with different quadrature rule is an error.)
> 
> Martin

Kent