[ferret_users] stiff modulo argument of x-axis

[Martin Schmidt <martin.schmidt@xxxxxxxxxxxxxxxxx>]

Hi,
I have a given regional data set stored in a netcdf-file topo.dta.nc. 
The axes are lat/lon, no modulo attribute is defined.

I derive a new variable from a variable in the data set and hope to have 
it defined at the same axis. For example:

let htp_closed = if i[gx=htp] eq 1 the 1/0 else htp

My choice would be to append the variable to the existing file. However, 
I cannot force ferret to use the same axis, xt_i, yt_j.
Instead two new capital XT_I, YT_J show up which are stored separately 
and have new attributes different from
the original axes. This confuses a program to read the data later.

Putting the new variable onto the old grid using @asn does not help either.

So I try to write to a new file;

save/clobber/file=my_new_file.nc htp_closed

Doing so, I get the modulo attribut set to 360 in the x- axis.

can axis/modulo `htp_closed,return=xaxis`

does not remove the modulo attribute. Also using the explicit axis name 
does not help.

How can I get rid of the wrong modulo attribute in the frame of ferret?

Would it be possible to change the behaviour of ferret in future 
releases in such a way,
that a modulo attribute must be set if it is required and correct, or is 
inherited from other axis that are modulo?

Dealing with regional data the automatic choice of ferret is always 
wrong and it reveals as very stiff to
produce correct data.

Many thanks,
Martin Schmidt