[CF-metadata] Interpretation of Compression by Gathering method

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 02 Jun 2011 12:43:37 -0000

Dear Phil

> The final sentence of chapter 8, in referring to example 8.2, reads:
> "This information implies that the salinity field should be uncompressed
> to an array with dimensions (depth, lat, lon)".
>
> I wonder if that should actually read "(time, depth, lat, lon)"?
Yes, I think you are right.

> Regardless, the implication seems to be that missing elements in the
> uncompressed array should take on the missing/fill value. Is that the
> correct interpretation?
Yes, I think so. That should be implied by its saying "invariably missing" in
the first sentence. It could be clarified by saying "invariably missing data"
instead.

We could make these minor changes with a trac defect ticket.

I agree that per-variable compression should be preferred and that this
could be noted in the CF standard, though I think that's a change rather than
a defect. We do know that compression by gathering is used because there was
a question about it on this email list just the other day!

Best wishes

Jonathan
Received on Thu Jun 02 2011 - 06:43:37 BST