Re: [ferret_users] modulo longitude standards?

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Steve,

Thanks for your detailed explanation.

> An axis may be less than global (e.g. axis "x30") and still be understood to
> have modulo 360 behavior.  This is inferred automatically from its units of
> degrees_east.   To reliably regard a variable defined on an X axis of more
> than 360 degrees, Ferret would have to check that the overlapping points at
> each end all had identical values.

Or you COULD just issue a warning and disregard the values on one of
the overlapping "layers".  I'm not saying you SHOULD.

>  Ferret has no internal logic to do this.

Yes, I guessed that that is the reason why Ferret currently rejects
such an overlapping axis.

> P.S.  The attribute "modulo" is from older Ferret versions.

So, what's the latest alternative?  Is it a Ferret-specific attribute?
 Or is it part of a well-recognized convention like CF?

The dataset I was given actually includes the "modulo" attribute.  I'm
not sure if the creators of the dataset use Ferret.

Basically, I'd like to know if I should ask the creators to fix it.
They are a data center and so they do care about these things.

Ryo