Hello ferreters,Dear Mark:I am trying to use a netCDF file with the calendar type set to "noleap",
and perform a climatology calculation in the FAQ titled "How do I
calculate climatologies and climatological anomalies?"The case using the navy winds works fine (where the calendar type
defaults to "Gregorian") - but if I use a "noleap" calendar
and try to plot (for e.g.) the climatology over the desired period
(using say the "month_reg" definition as in the FAQ example),
it fails with**ERROR: regridding: only @ASN, @LIN, or @NRST regridding between calendar
types: NOLEAP, GREGORIANrather than plotting out the repeaing annual (climatological) cycle.
I thought that this would work nicely with the "noleap" calendar, or
am I doing something wrong here?
I believe the problem is that the month_reg axis uses Gregorian months
i.e. 1/12 of 365.2425 days.
One solution is simply to define your own climatological axes, which
is easy for the regular months at
least.....
Explanation in ferret:
SET DATA monthly_navy_winds
SHOW grid/T uwnd
% note the 730.5 hour tboxes....
SET LIST/precision=8
% which is a Gregorian month:
LIST 365.2425*2
% I guess you want a shorter month:
LIST 365*2
% Here's how I would define it (perhaps there's a cleaner solution that
isn't missing a second at the end!)
DEFINE axis/T=01-JAN:"31-DEC:23:59:59"/edges/npoints=12/modulo/calendar=noleap
month_reg_noleap
% data on a leap calendar, plotted at date line to show it's well defined:
LET uwnd_clim = uwnd[GT=month_reg_noleap@MOD]
PLOT uwnd_clim[x=180,y=35n]
% get it on a no_leap calendar (as a proxy for your data)
DEFINE axis/T=01-JAN-1982:31-DEC-1992:1/unit=month/calendar=noleap/edges
tax_noleap
LET uwnd_noleap = uwnd[GT=tax_noleap]
% now going from no leap to no leap so it's okay:
LET uwnd_clim = uwnd_noleap[GT=month_reg_noleap@MOD]
% ... Bob's your uncle:
PLOT uwnd_clim[x=180,y=35n]
hope this helps,
Rob
Ideally I would like to use my own "climatological_axes" file which
has the month_irreg definitions (including edges) for a 365 day
calendar, but I suppose that is the next step.I can provide datasets, printouts of t and tbox, but I don't think
that is important just at the moment. I am using the latest version of
ferret under rehat, but I get the same response on the latest version for
irix.Thanks for any help. Regards,
Mark.
-- Postal Address: Program in Atmospheric and Oceanic Sciences P.O. Box CN710, Sayre Hall Princeton, NJ 08544-0710 USA Tel: 609-452-6519 o__ ____ Fax: 609-987-5063 _,>/'_ ----- E-mail: rscott@princeton.edu (_) \(_) ------