Subject: [FFC-dev] boundary integrals

From: "Garth N. Wells" <[email-masked]>
Date: Thu, 28 Sep 2006 15:48:30 +0200

Could we add something to the FFC output to indicate the
presence/absence of interior and boundary integrals? Then we can skip
the interiors/boundary assembly loop in DOLFIN if there are no
interior/boundary terms.

Garth

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From: Anders Logg <[email-masked]>
Date: Thu, 28 Sep 2006 17:33:50 +0200

> the interiors/boundary assembly loop in DOLFIN if there are no

Yes, I have wanted to do this before, but never gotten around to doing
it. It's a simple fix that I can fix quickly.

This would take care of the BLAS format for cases when there are no
boundary contributions?

/Anders

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From: "Garth N. Wells" <[email-masked]>
Date: Thu, 28 Sep 2006 17:42:11 +0200

> This would take care of the BLAS format for cases when there are no

It should do. I do however recall some problems with the Intel compiler
when not supplying a function for the boundary integral, but this could
be fixed with a compiler flag.

Garth

> /Anders
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-- 

Dr. Garth N. Wells
Faculty of Civil Engineering and Geosciences
Delft University of Technology
Stevinweg 1
2628 CN Delft
Netherlands

tel.   +31 15 278 7922
fax.   +31 15 278 6383
e-mail [email-masked]
url    http://www.mechanics.citg.tudelft.nl/~garth

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From: Anders Logg <[email-masked]>
Date: Thu, 28 Sep 2006 17:48:53 +0200

> be fixed with a compiler flag.

I'll just add a function that answers true or false on whether or not
there is a boundary contribution. The function is supplied (but empty)
even if there is no contribution.

/Anders

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From: Anders Logg <[email-masked]>
Date: Thu, 28 Sep 2006 18:30:18 +0200

On Thu, Sep 28, 2006 at 05:48:53PM +0200, Anders Logg wrote:
> DOLFIN-dev mailing list
> [email-masked]
> http://www.fenics.org/mailman/listinfo/dolfin-dev

Should be fixed now in both FFC and DOLFIN. Check if it works.

The logic in the assemble functions is getting a little to
complicated: three forms a, L and M are assembled simultaneously and
each form may or may not be a null pointer and if the pointer is
nonzero then there may or may not be an interior contribution and
there may or may not be a boundary contribution.

/Anders

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From: "Garth N. Wells" <[email-masked]>
Date: Thu, 28 Sep 2006 18:58:03 +0200

> there may or may not be a boundary contribution.

Yes, this is starting to look nasty. I can take a look at cleaning it up
by adding some small inlined functions to compute and insert each
element matrix/vector.

Garth

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From: Anders Logg <[email-masked]>
Date: Thu, 28 Sep 2006 21:10:05 +0200

> by adding some small inlined functions to compute and insert each

Sounds good.

Anyhow, we're up for a rewrite of the assembly, including updates for
the new mesh library (which should remove the need for templating the
assembly) and updates for the new FFC interface (UFC).

/Anders