I think I'm (slowly) getting this, but a few thoughts on language: "the CF data model is independent of the encoding, and the symmetric matrix is logically what is going on here."
That makes sense but the language I first noticed said a "symmetric array" -- I think we need to be careful about the abstraction of a symmetric matrix and the realization of an "array" in code, or a netcdf file, or ... And it needs to be clear that it's a abstract (sparse) boolean matrix, rather than an actual array (necessarily). "The nodes (i.e. bounds) and edges do not have an independent existence - they are elements of the CF cell definition. The new domain topology construct makes explicit the cell connectivities." That makes sense -- that is the whole point after all :-) " A "domain axis" is essentially a dimension of the domain. We restrict the new domain topology constructs to apply to a single domain axis simply because there is no current way of encoding a domain topology construct that applies to multiple domain axes. UGRID only describes a mesh with a 1-d discrete axis." Now I'm getting confused again -- I think this is (at least in my head) a result of a fundamental mismatch between orthogonal meshes and unstructured meshes. The whole concept of an "axis" matches orthogonal coordinates of some sort. (that's kind the definition of orthogonal, yes?). Mapping a Ugrid to the real world, the real world is 2D (Or 3D, but let's not go there yet) -- and that 2D world has 2 orthogonal axis -- X, Y, Lat, Long, whatever. So a mesh represents a 2D space -- but I wouldn't say it has two axes, or a 1-d discrete axis either, ir is simply something else. Or "axis" means something different in this context than I think it does. "separate domain definitions for each data variable is an appropriate view for the CF data model. " That means there *could* be separate definitions, or data variables could share the same one, yes? If, for instance, multiple variables in the same file are on the same mesh, they share a single domain definition, yes? Thanks for taking the time to educate me! -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://urldefense.us/v3/__https://github.com/cf-convention/cf-conventions/issues/153*issuecomment-887925192__;Iw!!G2kpM7uM-TzIFchu!l25fGL1Spt51msDlCyYHO35_-m5A_TRr12eoj7ksr2j_Dqr1L0uiRCmDLxF85lyapYwtjoW2xeY$ This list forwards relevant notifications from Github. It is distinct from [email protected], although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to [email protected].
