ufl team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Martin Sandve Alnæs wrote:
> On Fri, Jan 2, 2009 at 11:56 AM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
> > Kent Andre wrote:
> > > 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!
> > Looks good to me too.
> >
> > > > 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.
> > Agree.
> >
> > Garth
>
> Ok. What is the natural behaviour of this case then?
>
> myform.ufl:
> ...
> a = u*v*dx(0) + f*v*dx(1, 3)
>
> sfc -isymbolic myform.ufl
>
> I guess the compiler here can apply commandline integration options to
> dx(0) which is unspecified, and apply 3rd order quadrature to dx(1)?

That would be good.

I have some forms for which I always want to use quadrature, so it would 
be useful if this can be specified in the input rather than always on 
the command line.

Garth

> Martin