From: Roy Stogner <roystgnr@ic...>  20090116 22:45:32

On Fri, 16 Jan 2009, Brent Kraczek wrote: > It says that vec (internally, _vector) holds the data to be > interpolated. I thought this was part of eqn_system . There's two catches here: First: if you want to pick a vector from eqn_system, which one? If your EquationSystems object has three System objects in it, each of which has two vectors, that's six possibilities. Second: the vector you pick currently has to have enough information on it for MeshFunction to evaluate the points you ask it to  and if you're running in parallel, the vectors in your EquationSystems object are only going to have information on local and possibly ghost degrees of freedom. In that case you need to create a serialized vector to give MeshFunction; see the hack in exact_error_estimator.C for an example. > I appears to me that var/vars is supposed to be the number of the > attached variables (in this case, just "u"). Since I have only one > field, should this be '0'? Yes. > Finally, I'm not completely sure what FunctionBase does (am I okay > leaving it blank). There's a PointLocator octree that MeshFunction uses to find containing elements faster; if you build more than one MeshFunction you can hand the first to the second to tell them to share the same octree and save a little CPU/RAM.  Roy 