ufl team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Mon, Feb 16, 2009 at 09:28:09AM +0000, Garth N. Wells wrote:
>
>
> Anders Logg wrote:
>> On Mon, Feb 16, 2009 at 09:57:26AM +0100, Martin Sandve Alnæs wrote:
>>> On Sun, Feb 15, 2009 at 10:10 PM, Anders Logg <logg@xxxxxxxxx> wrote:
>>>> On Fri, Feb 13, 2009 at 02:30:00PM +0100, Martin Sandve Alnæs wrote:
>>>>> Attaching metadata to an integral is implemented, but we
>>>>> haven't  decided what format the metadata should be in.
>>>> I think there needs to be a convention as part of UFL for how to
>>>> specify the integration rule. Otherwise different form compilers will
>>>> invent different conventions and interpret the metadata differently.
>>> Agree.
>>>
>>>> Here's a suggestions:
>>>>
>>>>  metadata = ("quadrature", degree)
>>>>  metadata = ("tensor", degree)
>>> Here you're already into FFC territory...
>>>
>>> Integration order is an important mathematical
>>> property, the method for code generation is not.
>>> "tensor" is in the latter category.
>>
>> Hints for the degree of the quadrature is also form compiler
>> specific. There may be other ways to evaluate the integral than
>> quadrature, for example by random sampling, symbolic integration (like
>> in SyFi) or using a tensor representation (FFC).
>>
>
> Tensor representation still uses quadrature, it's just that it's  
> performed a priori rather than at runtime.
>
> Garth

Yes, but it may potentially be performed without use of quadrature.

I think the suggestion by Martin is ok. I just want to point out that
quadrature is not universally used by all form compilers.

-- 
Anders

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