ffc team mailing list archive

[Andy Ray Terrel <aterrel@xxxxxxxxxxxx>]

On Fri, Mar 26, 2010 at 7:45 AM, Kristian Oelgaard
<k.b.oelgaard@xxxxxxxxx> wrote:
>
>
> On 26 March 2010 13:36, Andy Ray Terrel <aterrel@xxxxxxxxxxxx> wrote:
>>
>> Could you have ffc print out a warning so dumb users like me will
>> remember this change when their code breaks?
>
> That might be a good idea, would it be enough to put in the __add__ operator
> in UFL for FiniteElements?
> We didn't use __mul__ before so we don't have to put a waring in there
> although we could do that.
> Then after a few releases we can remove the warnings again, once the dumb
> users have gotten used to the new syntax. :)


Sounds good to me.

-- Andy

>
> Kristian
>
>> -- Andy
>>
>> On Mon, Mar 22, 2010 at 1:14 PM, Marie Rognes <meg@xxxxxxxxx> wrote:
>>>
>>> Anders Logg wrote:
>>>>
>>>> On Mon, Mar 22, 2010 at 01:43:41PM +0100, Marie Rognes wrote:
>>>>
>>>>>
>>>>> Marie Rognes wrote:
>>>>>
>>>>>>
>>>>>> Anders Logg wrote:
>>>>>>
>>>>>>>
>>>>>>> On Mon, Mar 22, 2010 at 11:41:42AM +0100, Marie Rognes wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> Anders Logg wrote:
>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mon, Mar 22, 2010 at 06:20:00PM +0800, Garth N. Wells wrote:
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 22/03/10 16:42, Kristian Oelgaard wrote:
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On 21 March 2010 21:32, Anders Logg <logg@xxxxxxxxx> wrote:
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> After Marie's latest addition of enriched spaces (and
>>>>>>>>>>>> some discussion
>>>>>>>>>>>> with Doug Arnold), it seems clear that our current
>>>>>>>>>>>> notation V + W for
>>>>>>>>>>>> mixed spaces is not optimal.
>>>>>>>>>>>>
>>>>>>>>>>>> Even though one may think of the operation of creating a "mixed
>>>>>>>>>>>> function space" as a direct sum,
>>>>>>>>>>>>
>>>>>>>>>>>> X = {(v, 0) : v in V} \oplus {(0, w) : w in W},
>>>>>>>>>>>>
>>>>>>>>>>>> it is more natural (and common) to think of it as a
>>>>>>>>>>>> Cartesian product,
>>>>>>>>>>>>
>>>>>>>>>>>> X = V \times W = {(v, w) : v in V, w in W}
>>>>>>>>>>>>
>>>>>>>>>>>> It would therefore be more natural to use '*' instead of '+' as
>>>>>>>>>>>> the
>>>>>>>>>>>> operation for creating mixed elements/function spaces.
>>>>>>>>>>>>
>>>>>>>>>>>> That would free up '+' to be used for enriched spaces (which
>>>>>>>>>>>> have
>>>>>>>>>>>> recently been added),
>>>>>>>>>>>>
>>>>>>>>>>>> X = {v + w : v in V, w in W}
>>>>>>>>>>>>
>>>>>>>>>>>> The typical example would be to take V piecewise
>>>>>>>>>>>> linears and W scaled
>>>>>>>>>>>> P3 bubbles.
>>>>>>>>>>>>
>>>>>>>>>>>> In summary, the suggestion is to use the following notation:
>>>>>>>>>>>>
>>>>>>>>>>>> + <-->  +
>>>>>>>>>>>> * <-->  \times
>>>>>>>>>>>>
>>>>>>>>>>>> It's obvious this is better than what we have now which is
>>>>>>>>>>>>
>>>>>>>>>>>> + <--> \oplus
>>>>>>>>>>>> ? <--> +
>>>>>>>>>>>>
>>>>>>>>>>>> Thoughts?
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Agree.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Me too.
>>>>>>>>>>
>>>>>>>>>> Garth
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ok. Let's change then.
>>>>>>>>>
>>>>>>>>> It will require changes in both UFL and FFC. Anyone up for it?
>>>>>>>>>
>>>>>>>>
>>>>>>>> I can fix ffc.
>>>>>>>>
>>>>>>>
>>>>>>> I was hoping for that. :-)
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> (Have no permission for ufl)
>>>>>>>>
>>>>>>>
>>>>>>> You do now. ;-)
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> Aka, I'll fix that too.
>>>>>>
>>>>>>
>>>>>
>>>>> Fixed:
>>>>>
>>>>> (a) ElementUnion is now called EnrichedElement.
>>>>>
>>>>> (b) (Old) V + Q --> (New) V * Q
>>>>>
>>>>> (c) V + Q = EnrichedElement(V, Q)
>>>>>
>>>>>
>>>>> Now, PYDOLFIN needs updating...
>>>>>
>>>>
>>>> Done.
>>>>
>>>
>>>
>>> Great! (I'm off to do some Mini debugging.)
>>>
>>> --
>>> Marie
>>>
>>> _______________________________________________
>>> Mailing list: https://launchpad.net/~ffc
>>> Post to     : ffc@xxxxxxxxxxxxxxxxxxx
>>> Unsubscribe : https://launchpad.net/~ffc
>>> More help   : https://help.launchpad.net/ListHelp
>>>
>>
>> _______________________________________________
>> Mailing list: https://launchpad.net/~ffc
>> Post to     : ffc@xxxxxxxxxxxxxxxxxxx
>> Unsubscribe : https://launchpad.net/~ffc
>> More help   : https://help.launchpad.net/ListHelp
>>
>
>