Dear ferret users,
I am having problems regridding the time axis of a 20 year time series of monthly mean model output. Here's what I am doing:
yes? use my_Z_data_20yr.nc
!Read in data containing Julian day values for 20 years on a "noleap" calendar
yes? file/variable=jday/columns=12/type=numeric "20year_axis.dat"
!Define new time axis
yes? define axis/t0=31-Dec-2000/from_data/units=days/calendar=noleap tax_jday=tjday
!Regrid original variable to tax_jday
yes? let new_var = old_var[gt=tax_jday@asn]
!Save new variable (using Jaison Kurian's memory tricks)
yes? let l_start = `new_var,r=lstart`
yes? let l_end = `new_var,r=lend`
yes? let slices = l_end - l_start + 1
yes? REPEAT/L=`l_start`:`l_end`:1 (;\
save/file="my_outfile.nc"/append/quiet new_var ; \
say " Time slice `(L-l_start+1)`/`slices`" ;\
)
I then get the following error message:
!-> REPEAT: L=1
**TMAP ERR: error in line definition
disordered output coordinate value: 15.500 Axis: TAX
LIST/FORMAT=CDF/file="my_outfile.nc"/append/quiet new_var
Command file, command group, or REPEAT execution aborted
(I'm guessing TAX is a truncation of tax_jday?).
Just to confirm that the old and new time axes are of the same size:
yes? show axis time
name axis # pts start end
TIME TIME 240 i 01-FEB-2001 00:00 01-JAN-2021 00:00
T0 = 01-SEP-2000 00:00:00
CALENDAR = NOLEAP
Axis span (to cell edges) = 7300
yes? show axis tax_jday
name axis # pts start end
TAX_JDAY TIME 240 i 15-JAN-2001 12:00 15-DEC-2020 12:00
T0 = 31-DEC-2000
CALENDAR = NOLEAP
Axis span (to cell edges) = 7299
A related question: Is there a way to generate tax_jday in ferret, rather than read it in? I thought about adding multiples of 365 to an array of mid month, Julian day values (midmonth = {15.5, 45.0, 74.5, 105.0, 135.5, 166.0, 196.5, 227.5, 258.0, 288.5, 319.0, 349.5}) to get the 240 element array, but I couldn't think how to do it in ferret. Is it possible to concatenate user defined arrays into one variable (e.g. like let big_array={array1,array2,....,arrayN})? I don't have XCAT etc on my version of ferret, though I guess that might be the solution....
Thanks for any help,
Paul
-----
Paul Young
Chemistry and Climate Processes
Chemical Sciences Division
NOAA Earth System Research Laboratory
325 Broadway R/CSD8
Boulder CO 80305-3328
USA
Tel: +1 303-497-4943
Fax: +1 303-497-5686