ufl team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

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.

> > 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.

Garth


> Martin