thanks @JonathanGregory: that is better. Final note on "axis" -- I think I'm being pedantic here, and it's probably bad to introduce new terms, but:
David wrote: > A "discrete axis" in CF is one which does not correspond to a continuous > physical quantity, for example, this is the case for an axis that runs over > ocean basins or area types, or for a domain axis that indexes a time series > at scattered points. This also applies to the axis that stores the nodes of a > UGRID mesh. Does it though? > In many of these cases the discrete axis is sampling a higher dimensional > space, as you say. This where the "discrete sampling geometries" of chapter 9 > get their name (I always imagine a ship sailing along a sinuous course and > recording SSTs at various time intervals). A domain that has such a discrete > domain axis construct can also have other domain axis constructs (such as > ones for time, level, etc.) which are indeed orthogonal to each other and to > the discrete axis. In all of these examples, the axis may be "wandering around" in a higher dimensional space, but as noted, they are still orthogonal to others, and more critically, they represent a continuum of some sort. That is, where along the axis they lie is meaningful -- the fact that a value comes before or after another value, or is "next to" a value is meaningful. But in the case of a unstructured grid's node array, for instance, the order in which the node coordinates are in the array is completely (well, not completely, but ...) arbitrary. It is a mapping between a node index and the coordinates of that node, nothing more -- it could be completely re-ordered without its meaning changing. Which is why I don't think of it as an axis, even if it technically fits the definition. But as I said, probably good enough, and I can't think of a better term. -- 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-889300399__;Iw!!G2kpM7uM-TzIFchu!i2eIVZeGabCzH4ExsKvKNXNdu7uMRyewW_ZrajyYW6qm5tgx1n2Ije2xVYhT4Tx8M_z_er0a42c$ 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].
