partial answer to my own question

Hi Again,
   Not completely satisfied with my question, I worked on it some more.
I realized that I was not assigning the Fill Value attribute correctly.

I was setting all the Fill Values like:
integer_FillValue = -999

I think it's more correct to do the following:
integer_type = new(1,"integer")
integer_FillValue = getVarFillValue(integer_type)

Thus, when integer_FillValue is assigned to my attached attribute
quasi-variable, the _FillValue attribute of integer_FillValue seems to
also get passed along and ismissing works as expected. Another option
would be to use the assignFillValue procedure to transfer the metadata.
I'm not sure why this works, as I don't think that an attribute can be
attached to an attribute, but for some reason, this fixes my problem.
I've attached a script (now with 5 cases) illustrating which ways work
and which don't for those who are interested.

But I'd still like comments on my big-picture question from before - is
my approach of passing lots of variables as attached attributes a good
one? I think it's slightly better than just declaring everything
globally. Is there a better way to do this? Or should I go back to
traditional variable passing?

Thanks,
    Jonathan

;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Test the feasibility of passing arguments to functions as
; attributes rather than variables.
;*****************************************************************
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
;********************************************************

; global parameters

; this (what I had before) is probably not the "mother-approved" way to assign the Fill Value
bad_integer_FillValue = -999

; I think this method is more kosher:
integer_type = new(1,"integer")
integer_FillValue = getVarFillValue(integer_type)

procedure do_stuff(CONTAINER)
local stuff

begin

  CONTAINER_at_variableB = bad_integer_FillValue
  CONTAINER_at_variableC = integer_FillValue
  assignFillValue(integer_FillValue,CONTAINER_at_variableD)
  assignFillValue(bad_integer_FillValue,CONTAINER_at_variableE)

  print("In procedure . . .")
  print("variableA = "+CONTAINER_at_variableA+" ismissing? "+ismissing(CONTAINER_at_variableA))
  print("variableB = "+CONTAINER_at_variableB+" ismissing? "+ismissing(CONTAINER_at_variableB))
  print("variableC = "+CONTAINER_at_variableC+" ismissing? "+ismissing(CONTAINER_at_variableC))
  print("variableD = "+CONTAINER_at_variableD+" ismissing? "+ismissing(CONTAINER_at_variableD))
  print("variableE = "+CONTAINER_at_variableE+" ismissing? "+ismissing(CONTAINER_at_variableE))
  print(" ")

end

; main program
begin
  
  CONTAINER = True
  CONTAINER_at_variableA = new(1,"integer",bad_integer_FillValue)
  CONTAINER_at_variableB = new(1,"integer",bad_integer_FillValue)
  CONTAINER_at_variableC = new(1,"integer",integer_FillValue)
  CONTAINER_at_variableD = new(1,"integer",integer_FillValue)
  CONTAINER_at_variableE = new(1,"integer",integer_FillValue)

  print("In main program . . .")
  print("variableA = "+CONTAINER_at_variableA+" ismissing? "+ismissing(CONTAINER_at_variableA))
  print("variableB = "+CONTAINER_at_variableB+" ismissing? "+ismissing(CONTAINER_at_variableB))
  print("variableC = "+CONTAINER_at_variableC+" ismissing? "+ismissing(CONTAINER_at_variableC))
  print("variableD = "+CONTAINER_at_variableD+" ismissing? "+ismissing(CONTAINER_at_variableD))
  print("variableE = "+CONTAINER_at_variableE+" ismissing? "+ismissing(CONTAINER_at_variableE))
  print(" ")
 
  do_stuff(CONTAINER)

  print("In main program . . .")
  print("variableA = "+CONTAINER_at_variableA+" ismissing? "+ismissing(CONTAINER_at_variableA))
  print("variableB = "+CONTAINER_at_variableB+" ismissing? "+ismissing(CONTAINER_at_variableB))
  print("variableC = "+CONTAINER_at_variableC+" ismissing? "+ismissing(CONTAINER_at_variableC))
  print("variableD = "+CONTAINER_at_variableD+" ismissing? "+ismissing(CONTAINER_at_variableD))
  print("variableE = "+CONTAINER_at_variableE+" ismissing? "+ismissing(CONTAINER_at_variableE))
  print(" ")
 
 
end

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Received on Fri Nov 28 2008 - 15:49:25 MST