Subject: [FFC-dev] operations in FFC

From: [email-masked]
Date: Fri, 2 Sep 2005 09:43:16 +0200 (MEST)

Anders,

Some operations for Functions in FFC that would be very useful are:
multiplication, division, and powers, including taking the square root,
with the operations defined as the corresponding operations for the nodal
values.

Together with access to a local (cell) h in some form, I think we will be
able to implement a wide range of solvers in Dolfin.

/Johan

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From: Anders Logg <[email-masked]>
Date: Fri, 2 Sep 2005 08:04:02 -0500

> with the operations defined as the corresponding operations for the nodal

What do you mean by multiplication? FFC already does
multiplication. Do you mean interpolating a product w1*w2 to remove
one of the factors in the output to reduce the complexity of evaluation?

> able to implement a wide range of solvers in Dolfin.

I agree. All this will be added.

There are a couple of things I need to implement in FFC. Which is the
most important? Which should be implemented first?

1. Improve the expressiveness of the form language: division, powers,
square root, predefined h, index ranges (for Garth), operators such as
grad(), rot(), div(), unit tensor etc.

2. Boundary integrals using *ds.

3. Option -f blas for generating BLAS output (to speed up compilation of
complicated forms).

I should be able to start implementing one of these early next week.

/Anders

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From: [email-masked]
Date: Fri, 2 Sep 2005 16:30:27 +0200 (MEST)

> one of the factors in the output to reduce the complexity of evaluation?

Sorry, multiplication should not have been there.

> I should be able to start implementing one of these early next week.

I'd say: 1-3-2

/Johan

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From: Anders Logg <[email-masked]>
Date: Fri, 2 Sep 2005 09:46:37 -0500

> > I should be able to start implementing one of these early next week.

ok, sounds good. I'll get to work. Things should start to make their
way into CVS, beginning next week.

/Anders