fenics team mailing list archive

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

On 16 June 2010 22:09, Anders Logg <logg@xxxxxxxxx> wrote:
> Looks good. I noticed a couple of things:
>
> 1. It would be good if class names were in another font (like courier
> style), \texttt{VariationalProblem} etc

Once the Programmer's reference is up and running, I think we should
just use links to the class documentation (and member functions).

> 2. Would it be better with another variable name instead of h since
> that will be used as mesh size in other demos. Why not g?

I'll change h --> g for all Neumann BCs.

> 3. Is the normal flux + or - grad(u).n? I think of it as -grad(u).n.

The equation is:

- \Delta u = f

multiplying by v:

- v \Delta u = vf

integration by parts and switching to UFL:

inner( grad(v), grad(u))*dx  - v*inner(grad(u), n)*ds = v*f*dx

if we use g = - inner(grad(u), n) then

inner( grad(v), grad(u))*dx  + v*g*ds = v*f*dx

so

a = inner( grad(v), grad(u))*dx
L = v*f*dx - v*g*ds

then we need to use g = sin(5x) for the demo to give the same solution.

Of course we can move the '-' from L to g (which is what we have now)
but then the form does not follow directly from our equations.

> 4. Typo in "The implemented in a single Python file"

Fixed.

> 5. g is used in (f, g) instead of h (but maybe h should be changed to g)

yes.

> The documentation seems to be coming along pretty well. It may be time
> for you to ask people to contribute specific parts. For example,
> Johannes and Harish could contribute with some documentation of how to
> get Debian/Ubuntu packages and building with Dorsal. Others can
> contribute with writing specific pages for the programmer's
> reference, and Hans Petter can contribute with preparing his tutorial
> in reST (and split it in Python and C++ versions).

I need to figure out the framework for the Programmer's reference and
write the styleguide for contributing, but the Tutorial and
Installation parts can be written now.

Kristian

> --
> Anders
>
>
> On Wed, Jun 16, 2010 at 06:31:42PM +0200, Kristian Oelgaard wrote:
>> Hello,
>>
>> I've finished a first iteration on documenting the Poisson demo (from
>> dolfin/demo/pde/poisson).
>>
>> Check it out and let me know what you think.
>>
>> The Python version is here:
>>
>>  http://www.fenics.org/newdoc/demos/python/pde/poisson/poisson.html
>>
>> and the C++ version is here:
>>
>> http://www.fenics.org/newdoc/demos/cpp/pde/poisson/poisson.html
>>
>> Note that I need to finish the Programmer's reference part of the
>> documentation before I can insert links to the relevant classes used
>> in the demos.
>>
>> http://www.fenics.org/newdoc/programmers-reference/index.html
>>
>> Kristian
>>
>> _______________________________________________
>> Mailing list: https://launchpad.net/~fenics
>> Post to     : fenics@xxxxxxxxxxxxxxxxxxx
>> Unsubscribe : https://launchpad.net/~fenics
>> More help   : https://help.launchpad.net/ListHelp
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.10 (GNU/Linux)
>
> iEYEARECAAYFAkwZL2IACgkQTuwUCDsYZdHZ5QCfa7fC+zyjjYtWG2HncJVdtl/4
> UskAn0LZx1DNof5lIRs9/+TzPhNbaErU
> =esYb
> -----END PGP SIGNATURE-----
>
>