ufl team mailing list archive

[Andy Ray Terrel <aterrel@xxxxxxxxxxxx>]

Could you have ffc print out a warning so dumb users like me will
remember this change when their code breaks?

-- 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
>
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