missing values with month_to_seasonN

From: Will Hobbs <whobbs_at_nyahnyahspammersnyahnyah>
Date: Wed, 05 Sep 2007 17:05:53 PDT

('binary' encoding is not supported, stored as-is) Hi all

This is just a comment on a problem that I'm having with the
month_to_seasonN function. It may affect other functions but this is the
first time I've come across it.

I'm using SST from the hadisst dataset, which uses a _FillValue of 1e+20,
including land surface areas. See the following snippet, with comments....

  x = f1->sst

  print(x@_FillValue) ;correctly returns 1+e20
  print(num(ismissing(x))) ; if the data includes land surface, this
must be non-zero

  xSeas = month_to_seasonN(x, season)

   print(xSeas@_FillValue) ;returns 1+e20. fine

   print(num(ismissing(xSeas))) ;returns 0, wrong!
   
   print(num(xSeas.eq.xSeas@_FillValue)) ;again, incorrectly returns 0

   print(num(xSeas.eq.-999.)) ;returns a sensible answer

Of course it's easy enough to fix a workaround for this..

  xSeas@_FillValue = -999.

...but if you're not aware of this it can cause some unusual results
further down the line.

Will

  

============================
Will Hobbs
PhD Candidate
Room A113
UCLA Department of Geography
1255 Bunche Hall
Los Angeles CA 90095-1524
Tel: 310 663 2631

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Received on Wed Sep 05 2007 - 18:05:53 MDT