dolfin team mailing list archive

[Martin Sandve Alnæs <martinal@xxxxxxxxx>]

On Fri, Feb 27, 2009 at 4:08 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
>
>
> Martin Sandve Alnæs wrote:
>>
>> On Fri, Feb 27, 2009 at 4:03 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:
>>>
>>> Evan Lezar wrote:
>>>>
>>>> Hi
>>>>
>>>> I am working on some electromagnetic problems that require I model the
>>>> electric field as a complex phasor.  When compiling user-defined
>>>> functions I get an error message.
>>>>
>>>> For example, consider the following simple function:
>>>>
>>>> f = Function(V, '1.0j')
>>>>
>>>>
>>>> when calling the JIT compiler, the log shows the following error (in the
>>>> last couple of lines):
>>>>
>>>> dolfin_compile_function_934f16b21b1210d9244eba2ba7985a9a_wrap.cxx: In
>>>> member function ‘virtual void
>>>> dolfin::function_91ee55df622466fafbf3ba887ffb745e::eval(double*, const
>>>> double*) const’:
>>>> dolfin_compile_function_934f16b21b1210d9244eba2ba7985a9a_wrap.cxx:3221:
>>>> error: cannot convert ‘double __complex__’ to ‘double’ in assignment
>>>> error: command 'gcc' failed with exit status 1
>>>>
>>>> Does dolfin support complex valued functions?
>>>
>>> No.
>>>
>>> If so, how do I go about
>>>>
>>>> getting them working?  And if not, how do I go about adding the
>>>> functionality.
>>>>
>>> It would be a big task to make it seamless. The starting point would be
>>> having FFC (or soon UFL) support complex functions. I thought about this
>>> a few years ago but never got around to it.
>>>
>
> Thinking about, it shouldn't be too hard to patch something together using
> mixed elements.

Won't be as user-friendly as it could be though, but perhaps you
could define e.g. complex multiplication as python functions on top.


>>> UFL question: Does or will UFL support complex functions?
>>
>> No. And I don't think making such an addition before it has stabilised
>> is an option, we can't change everything everywhere simultaneously.
>>
>
> OK. Would be good for the long-term goals list.

Sure. I'll add it.

Martin