ufl team mailing list archive

[Kristian Oelgaard <k.b.oelgaard@xxxxxxxxxx>]

Quoting Martin Sandve Alnæs <martinal@xxxxxxxxx>:

> On Mon, Feb 23, 2009 at 11:23 AM, Kristian Oelgaard
> <k.b.oelgaard@xxxxxxxxxx> wrote:
> > Quoting Kristian Oelgaard <k.b.oelgaard@xxxxxxxxxx>:
> >
> >> Quoting Anders Logg <logg@xxxxxxxxx>:
> >>
> >> > I thought about it some more and I think I might be able to generate
> >> > the indices on the fly as part of the monomial extraction so it might
> >> > not be necessary.
> >> >
> >> > So if it's not needed for quadrature it can be part of the monomial
> >> > extraction. Otherwise, it seems pretty simple to make a transformer
> >> > for index renumbering.
> >>
> >> I don't think index renumbering is needed for quadrature. A thing that is
> >> needed, however, is the component number of functions/basisfunctions but
> is
> >> this
> >> alway represented by index?
> >
> > Sorry, 'index' should be Indexed in the above.
> >
> > Kristian
> 
> This question is too inaccurate for me to know what to say... But I'll try.
> 
> A (basis) function never _has_ an index, but expressions
> may refer to a component of a function using Indexed.
> However, you can also have e.g. sums of Functions
> on vector elements, and Indexed outside that.

Does this means that for

a = V[0].dx(1)*dx

one will have to return something like [V[0].dx(1), V[1].dx(1)] from
BasisFunction and then let Indexed pick the correct value? This looks very
inefficient and it makes it more complicated to know which variable names are
going to be used in the code.


BTW index renumbering breaks for

V[0]*V[1]*dx

Kristian

> Martin
> 
> 
> >
> >> Kristian
> >>
> >> > --
> >> > Anders
> >> >
> >> >
> >> > On Sun, Feb 22, 2009 at 10:35:06AM +0100, Martin Sandve Alnæs wrote:
> >> > > No, index renumbering isn't implemented.
> >> > > And basis function indices are nonexisting,
> >> > > I didn't think we needed them but maybe
> >> > > you do for the tensor representation.
> >> > > Lets discuss it next week.
> >> > >
> >> > > Martin
> >> > >
> >> > >
> >> > >
> >> > > On Sat, Feb 21, 2009 at 9:24 PM, Anders Logg <logg@xxxxxxxxx> wrote:
> >> > > > Is index renumbering implemented in UFL? I'd like to renumber all
> >> > > > indices in a form such that the first index starts at zero. I'd
> also
> >> > > > like to be able to have separate index types/flags for argument
> basis
> >> > > > functions and other indices.
> >> > > >
> >> > > > For Poisson, FFC renumbers from
> >> > > >
> >> > > >  (dXa10/dx0)(dXa11/dx0) | ((d/dXa10)vi-2)*((d/dXa11)vi-1)*dX(0) +
> >> > > >  (dXa12/dx1)(dXa13/dx1) | ((d/dXa12)vi-2)*((d/dXa13)vi-1)*dX(0)
> >> > > >
> >> > > > to
> >> > > >
> >> > > >  (dXa0/dx0)(dXa1/dx0) | ((d/dXa0)vi0)*((d/dXa1)vi1)*dX(0) +
> >> > > >  (dXa0/dx1)(dXa1/dx1) | ((d/dXa0)vi0)*((d/dXa1)vi1)*dX(0)
> >> > > >
> >> > > >
> >> > > > -----BEGIN PGP SIGNATURE-----
> >> > > > Version: GnuPG v1.4.9 (GNU/Linux)
> >> > > >
> >> > > > iEYEARECAAYFAkmgYxEACgkQTuwUCDsYZdEMCACfbxiYdEQrXpr9Ex5axYMqQ/Ja
> >> > > > PbAAnjPaJkzuhXyEwBxKnDi1peZrKx+Y
> >> > > > =OyGI
> >> > > > -----END PGP SIGNATURE-----
> >> > > >
> >> > > > _______________________________________________
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> >> > > >
> >> > > >
> >> >
> >>
> >>
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