>Multigrid may be the way to handle difficult 3-D fluid dynamics >problems, and is being explored by a number of adventurous >fluid dynamicists. > >Any netcdfers have ideas on representation strategies? > > --Barbara Mihalas bmihalas@ncsa.uiuc.edu I believe you need to address another issue first, namely, what do you want from a co-ordinate system "thingy". The types of behavior you'd like from it should help you determine what information it'll need to store. Once you have that, you can figure out the representation. Actually, a co-ordinate system "thingy" is probably the wrong level of abstraction at this point. Because datasets are intimately related to their co-ordinate systems (the co-ordinate system defines the independent variables after all) it's probably more useful to think of the required behavior of the dataset. I can imagine a dataset answering the following questions: Q: What's the type of your co-ordinate system? A: Geographic Q: How many co-ordinate systems do you contain? A: 3 Q: What's the projection of the first system? A: Cylindrical equidistant. Q: What are the parameters of the first system? A: ... Q: What's the datum closest to co-ordinates ...? A: ... Q: What are the co-ordinates of the datum at indexes ...? A: ... etc. I think we need to enumerate all the co-ordinate-system-related behaviors we'd like from datasets. --Steve