← Back to team overview

dolfin team mailing list archive

Re: Fwd: [Branch ~dolfin-core/dolfin/main] Rev 4734: Introduce functionality for automated error control and adaptivity.

 



On 09/05/10 21:08, Marie Rognes wrote:
Garth N. Wells wrote:


On 09/05/10 20:11, Anders Logg wrote:
On Sun, May 09, 2010 at 07:50:14PM +0100, Garth N. Wells wrote:


On 09/05/10 19:25, Anders Logg wrote:
On Sun, May 09, 2010 at 07:06:04PM +0100, Garth N. Wells wrote:


On 09/05/10 15:04, Marie Rognes wrote:
Garth N. Wells wrote:
Does this work from the C++ interface too?



Nope. It is a pure python prototype.


This isn't the design philosophy that we've used in developing
DOLFIN. We have developed in C++ (and I think still should) and
generated the Python interface automatically, and implemented Python
extensions by hand only when necessary. I don't want to see a
divergence of the interfaces and advocate that Python 'prototypes'
should not be part of DOLFIN.

Garth

I think this prototype is too good to be kept as a prototype. We will
move the things that can be moved to C++, but it might not be possible
to move all of it since it relies on automatic differentiation and
auto-generation of the dual problem.


Having Python-only parts when required is fine (like we do now), but
why not develop the C++ building blocks before committing to
dolfin-main?

Simply because we just finished the Python version and thought it
would be useful to others.

If the structure is clear and clean, it doesn't take much effort to
write the C++ code. By not adding the C++ code now, there is a
strong likelihood that it will never be added.

It's not unlikely. There is quite a strong commitment to moving parts
of it to C++.

I would prefer that prototypes remain in the sandbox until the C++
code is in place.

The addition of the Python adaptivity code marks a change in
development approach and should be discussed.

I'm not sure the sandbox is a good place (at least not in its current
form). It's a mixture of stuff that works and stuff that doesn't work,
things that are broken, test snippets etc.

If we decide to enforce a strong policy that we should not add
experimental code to DOLFIN,

The question is not on experimental code - it's preserving the
language-neutral nature of DOLFIN and whether we want to continue this
approach. I would like DOLFIN to remain language-neutral.

is there a way that we could organize
modules like the adaptivity module and make them easily installable?
I don't think it's a good idea to create things as separate projects,
if the intention is to merge it into DOLFIN. It would be something
between dolfin-sandbox and dolfin-main.


A DOLFIN-app? Once ready, it could be merged into dolfin-main. I would
like to have the adaptivity code in dolfin-main now (with C++ code),
but I'm too much of a cynic to be sold on assurances that C++ code
will be added ;). What's the driver if the code already meets the need
of the developer?



I don't think I'll embark on the philosophical issues. However,

(1) I take personal responsibility for adding this on the c++ side to
the extent this is possible (at least as long as it stays in dolfin-main
;) )h


Great! I look forward to it . . . soon ;).

(2) I'm envisioning having a hard time at explaning (potential) users
that "we can do this really cool thing, that nobody else can do, but we
do not want to make it easily accessible because of our language
philosophy".


Two points on the argumentation under (2):

(a) Code can always be made available. I've made Python-only code publicly available in support of papers, etc (e.g., http://www.dspace.cam.ac.uk/handle/1810/221687)

(b) What you describe under point (2) is exactly what Python-only features says to users of the DOLFIN C++ interface.

My point is our development model. The philosophy relates to the design/development process which we described in

  http://doi.acm.org/10.1145/1731022.1731030

and which I argue has worked pretty well so far. There is no language philosophy.

Garth



--
Marie




Follow ups

References