[CF-metadata] Reverse-time trajectory

From: Jonathan Gregory <j.m.gregory>
Date: Tue, 1 May 2012 16:02:54 +0100

Dear Richard

> The CF definitions of discrete sampling geometries define the "trajectory" feature type as "a series of data points along a path through space with monotonically increasing times". This is a stricter stance than the usual CF coordinate definition of "ordered monotonically". What was the reason behind the addition of the "increasing" constraint, and can it be relaxed? We have data sets where a model is run backwards in time.

Good point. I would think that "monotonically" would be enough, not necessarily
increasing. I can't remember a reason for "increasing"; I assume it's just
because sect 9 was conceived for observations in the first place. However, John
Caron may well have a comment. I don't think anything prevents your storing
the data in the orthogonal multidimensional representation, which existed
before sect 9 did and doesn't require increasing coordinates.

Best wishes

Jonathan
Received on Tue May 01 2012 - 09:02:54 BST