[pooma-dev] FieldStencils and Field(Range) views

[Nils H. Busch]

James Crotinger wrote:

>
>
> There is, in general, no good way to construct metric information for
> a range view of a field, which is why range views evaluate to Fields
> with NoGeometry. For instance, if you have a non-uniform
> non-orthogonal coordinate system and you remove every other point in
> one direction, the new mesh is no longer a simple sub-mesh of the old
> mesh, and there is no general way for Pooma to calculate this new
> information. For fields with cartesian coordinates this could be done,
> but such discrimination would have required the coordinate system type
> to be a compile time quantity, and in the re-design of Fields our main
> customers really wanted us to reduce the number of template
> dependencies (helps code-bloat, compile time, . . .).
>
>         Jim
>

Thanks for pointing this out.

How do I then proceed to write something like

lhs = Function(restriction(rhs(R)));

where lhs is a coarse resolution field, rhs a finer resolution field, R
some range and restriction a function that performs some restriction
operation from fine to coarse, so that the right hand side of the
assignment is transformed into a POOMA expression tree ( with as few
temporary fields as possible) ?

Any suggestions appreciated.


--
    Nils H. Busch
    Max-Planck-Institute of Cognitive Neuroscience
    phone:  ++49 (341) 9940-035 fax:  ++49 (341) 9940-204
    e-mail: nilsb at cns.mpg.de