[CF-metadata] Reverse-time trajectory

From: Jonathan Gregory <j.m.gregory>
Date: Fri, 18 May 2012 13:49:45 +0100

Dear Richard

> Does CF really need to support unordered elements *within* a single[1]
> time series? e.g. Are there a significant number of real-time situations
> where the data from a single stream need to be written out of order to a
> CF file?

I think that's a reason for having the ragged representation, which mentions
real-time data as a canonical use case. Data can arrive in the wrong order, I
expect, even if it doesn't happen often.

> So somewhat contrary to my previous statement, my current thinking is
> table 9.1 should keep the "monotonically" and "ordered" descriptions,
> and these should be clarified by further rules stating their ordered
> nature even when expressed as an aux coord var.

I think it would be possible make such a restriction if you use the featureType
attribute, which indicates that the rules of sect 9 apply. But the use of
auxiliary coordinate variables for time already existed before sect 9 was
written, in what sect 9 refers to as the orthogonal multidimensional
representation, and that can be used without the featureType attribute.

Why not sort the data into monotonic order of time before using it?

Best wishes

Jonathan
Received on Fri May 18 2012 - 06:49:45 BST