Re: climatologies

[hankin@xxxxxxxxxxxxxxxxxxx (Steve Hankin)]

Hi Emilio,

The misbehavior you describe is due to a bug in version 4.45 (and earlier) of
Ferret. It has been located and fixed and it will be OK in the next Ferret
version ... but (sigh) not in the version that you have. Here is an easy
work-around.

BUG:
  When using an @MOD regridding and requesting the last element of the
  modulo axis the data sometimes appear to be all missing values.
WORK_AROUND:
  The bug appears only in attempting to access the last element of the axis
   **alone**. To work around it make sure that you are requesting at least
   two points on the modulo axis.

EXAMPLE:
! this exhibits the bad behavior
   SHADE/L=12 EET_MEANYR

! but this is fine
   SHADE/L=12 EET_MEANYR[L=11:12]

! alternatively, this is also fine (by caching the correct result in Ferret)
   CANCEL MEMORY/ALL
   LOAD EET_MEANYR[L=11:12]	! cache a region of 2 points on the modulo axis
   SHADE/L=12 EET_MEANYR

I hope this helps.

	- steve

==========================================================

On Apr 10,  4:35pm, Emilio Mayorga wrote:
> Subject: climatologies
>
> I have some strange and inconsistent behavior when following the Ferret
> FAQ and Manual to create a climatology variable. Maybe from the
> description of the error, someone can give me a hint as to where to look?
>
> I create a climatology variable, EET_MEANYR, out of a 7-year (1983-89)
> monthly data set, EET:
>
> let EET_MEANYR = EET[gt=MONTH_REG@MOD]
> (the climatological axis MONTH_REG is from climatological_axes.cdf)
>
> EET_MEANYR can then be plotted as a time series, and all 12 months show
> up. It can be displayed using SHADE in the XT or YT planes, and
> everything's fine.
>
> BUT in the XY plane SHADE works with all months, EXCEPT DECEMBER! When I
> try dec, eg, SHADE/T=15-dec EET_MEANYR, I get an error message:
>  **ERROR: all data have same value: data are all flagged as bad
>
> Also, when I use STATISTICS to examine the values, when done on ALL
> points, no bad data is detected; but when done on december only (L=12 or
> T=15-dec), ALL POINTS APPEAR TO BE BAD!
>
>
> Any clues? I appreciate your help.
>
> Emilio Mayorga
> _________________________________________________________________
> University of Washington
> School of Oceanography			emiliom@u.washington.edu
> Box 357940				ph. (206) 543-5334
> Seattle, WA  98195-7940	  USA		FAX (206) 685-3351
> http://boto.ocean.washington.edu/staff_pages/emilio/
>
>-- End of excerpt from Emilio Mayorga