ufl team mailing list archive

[Martin Sandve Alnæs <martinal@xxxxxxxxx>]

2009/4/1 Johan Hake <hake@xxxxxxxxx>:
> On Wednesday 01 April 2009 01:19:14 Anders Logg wrote:
>> On Tue, Mar 31, 2009 at 11:38:08PM +0200, Johan Hake wrote:
>> > On Tuesday 31 March 2009 23:06:15 Anders Logg wrote:
>> > > On Tue, Mar 31, 2009 at 10:09:26PM +0200, Johan Hake wrote:
>> > > > On Tuesday 31 March 2009 21:24:21 Martin Sandve Alnæs wrote:
>> > > > > 2009/3/31 Anders Logg <logg@xxxxxxxxx>:
>> > > > > > On Tue, Mar 31, 2009 at 08:39:42PM +0200, Johan Hake wrote:
>> > > > > >> On Tuesday 31 March 2009 17:13:13 Martin Sandve Alnæs wrote:
>> > > > > >> > On Tue, Mar 31, 2009 at 3:55 PM, Anders Logg <logg@xxxxxxxxx>
>> >
>> > wrote:
>> > > > > >> > > On Tue, Mar 31, 2009 at 01:06:36PM +0200, Martin Sandve
>> > > > > >> > > Alnæs
>> >
>> > wrote:
>> > > > > >> > >> On Mon, Mar 30, 2009 at 7:48 PM,  <logg@xxxxxxxxx> wrote:
>> > > > > >> > >> >> I'm ok with the "forms / (a,L,M)" feature, and that
>> > > > > >> > >> >> pretty much solves the interpretation problem for (u,v)
>> > > > > >> > >> >> in that context. We should also have an optional list
>> > > > > >> > >> >> "elements" like "forms". I like
>> > > > > >> > >> >>   forms = [a, L]
>> > > > > >> > >> >> better, quotes are unnecessary.
>> > > > > >> > >> >
>> > > > > >> > >> > ok!
>> > > > > >> > >> >
>> > > > > >> > >> >> In the context of PyDOLFIN, PyDOLFIN can itself check
>> > > > > >> > >> >> for tuple or Form, so we don't need to check it
>> > > > > >> > >> >> everywhere.
>> > > > > >> > >> >
>> > > > > >> > >> > I don't think DOLFIN should need to check for this.
>> > > > > >> > >> > Wouldn't it be better to let the form compiler handle it?
>> > > > > >> > >> >
>> > > > > >> > >> > Which interfaces does SFC have? FFC has two interfaces:
>> > > > > >> > >> >
>> > > > > >> > >> > 1. The compile() command in FFC (takes a single object or
>> > > > > >> > >> > list of objects)
>> > > > > >> > >>
>> > > > > >> > >> compile is a builtin function in Python, so this should be
>> > > > > >> > >> renamed.
>> > > > > >> > >
>> > > > > >> > > Good point. I've been told this before (by Rob). Do you have
>> > > > > >> > > a good suggestion for a better name?
>> > > > > >> >
>> > > > > >> > I have
>> > > > > >> > def generate_code(input, options=None):
>> > > > > >> > def jit(input, options=None):
>> > > > > >>
>> > > > > >> Will this be different if we let ufc take care of the jit
>> > > > > >> compilation?
>> > > > > >>
>> > > > > >> I think,
>> > > > > >>
>> > > > > >>   def generate_code(input, options=None):
>> > > > > >
>> > > > > > I think it should be made more explicit:
>> > > > > >
>> > > > > >  def compile_form(form, options=None)
>> > > > > >  def compile_forms(forms, options=None)
>> > > > > >  def compile_element(element, options=None)
>> > > > > >  def compile_elements(elements, options=None)
>> > > > >
>> > > > > Why? It's convenient to share code between these.
>> > > >
>> > > > Agree.
>> > >
>> > > Yes, but that's an implementation issue. It's perfeclty fine to
>> > > implement compile form by
>> > >
>> > >   return compile_forms([form], options)
>> > >
>> > > or even
>> > >
>> > >   return _compile_objects([form], options)
>> > >
>> > > Having separate functions simplifies error checking on input.
>> >
>> > You meen that ufc provides a jit function. This function check what is
>> > provided and call the proper function, you mentioned above, which is
>> > provided by the formcompiler?
>> >
>> > Couldn't we just send the ufl input to generate_code(). Then we compile
>> > the extension module and based on the ufl input we try to instantiate the
>> > form(s) or finite element(s) and dofmap(s) and return these to the user.
>> > Based on the input we type check the instantiated objects and that is
>> > enough?
>>
>> Does the jit function need to know what type of objects it gets? If it
>> knows whether an object is a form or element, then it appropriate to
>> call either compile_form or compile_element. If not, then I agree it's
>> better to let the form compiler resolve the type of object.
>
> I vote for this. The interface between ufc.jit and the formcompiler will then
> be minimal, and that is good.
>
> I added the type check suggestion as a sanity check for what the formcompiler
> returns. But I do not think it is nescessary.

If we are supposed to handle a list of objects that can be a mixture of
elements and forms, it doesn't make any sense to split the implementations.
Since we have a single "jit" command, the types of the input must be
inspected anyway, so I don't really see what the splitting simplifies.

>> > > > > >>   def signature(input, options=None):
>> > > > > >>
>> > > > > >> make sense then.
>> > > > > >
>> > > > > > This looks like a function that just computes a signature.
>> > > > >
>> > > > > Because that's what it is? SFC has a similar function. I suggest
>> > > > > compute_signature.
>> > > >
>> > > > Sounds good.
>> > >
>> > > Aren't we talking about the call to the JIT compiler? What is
>> > > signature supposed to do?
>> >
>> > The jit function will be implemented in ufc. ufc needs to be able to
>> > compute a signature to check whether the form(s) or element(s) allready
>> > are compiled. This, as I have argued above but still not sure is right,
>> > is formcompiler specific.
>>
>> ok, then I understand. Should it be named something like compute_signature?
>
> I think that sounds good.
>
> Johan

Good.

Martin