[CF-metadata] Using add_offset & scale_factor with coordinate variables

From: Mike Grant <mggr>
Date: Fri, 13 Apr 2012 10:31:19 +0100

On 13/04/12 10:15, David Hassell wrote:
> That sounds reasonable to me. From a backwards compatibility view
> point, it sounds like any existing software built on the common netCDF
> libraries will already correctly interpret these attributes on
> coordinates ... is that a fair assumption?

>From what John wrote, I think anything written using the Java netCDF
libraries will unpack coordinates and interpret it correctly. However,
everything else (e.g. using the C libraries) will have to have coded in
their own unpacking support. I imagine a sizeable number (probably the
majority) haven't done so, even for data variables.

If one is purely seeking to reduce data size, and if the data are
suitable, it's certainly better to use netCDF4 internal compression as
this is fully and transparently supported in all libraries and requires
no specific application level code. Perhaps this could be included in
the unpacking section as a recommendation/point to consider? I'm aware
that the original poster was looking for other conveniences though.

Cheers,

Mike.
Received on Fri Apr 13 2012 - 03:31:19 BST