calculations with "undefined" variables...

[Charles Seman]

Hi,

Here are some results from a recent GrADS session...

-------

Grid Analysis and Display System (GrADS) Version 1.9b4
Copyright (c) 1988-2005 by Brian Doty and IGES
Center for Ocean-Land-Atmosphere Studies (COLA)
Institute for Global Environment and Society (IGES)
GrADS comes with ABSOLUTELY NO WARRANTY
See file COPYRIGHT for more information

Config: v1.9b4 32-bit little-endian readline sdf/xdf netcdf lats printim

...

ga-> set gxout print
ga-> set z 1
LEV set to 0.035 0.035
...
ga-> set x 1
LON set to 167.113 167.113
ga-> set y 1
LAT set to 8.31355 8.31355
ga-> d pp
Printing Grid -- 1 Values -- Undef = -9999.9
100603
ga-> d pp_dcreg
Printing Grid -- 1 Values -- Undef = -9999.9
-9999.9
ga-> define ppb = aave(pp_dcreg,x=1,x=64,y=1,y=64)
Define memory allocation size = 4 bytes
ga-> d ppb
Printing Grid -- 1 Values -- Undef = -9999.9
-9999.9
ga-> define ppb = aave(pp_dcreg,x=1,x=64,y=1,y=64)/100
Define memory allocation size = 4 bytes
Name already DEFINEd:  ppb.   Will be deleted and replaced.
ga-> d ppb
Printing Grid -- 1 Values -- Undef = -9.99e+33
-9.99e+33
ga-> d pp_dcreg/100
Printing Grid -- 1 Values -- Undef = -9.99e+33
-9.99e+33

-------

Is it true that GrADS always assigns -9.99e+33 to the result of scaling
an "undef" value?

Thanks,
Chuck

--

********************************************************************
 Charles Seman                                charles.seman at noaa.gov
 U.S. Department of Commerce / NOAA / OAR
 Geophysical Fluid Dynamics Laboratory         voice: (609) 452-6547
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 Princeton, NJ  08540-6649            http://www.gfdl.noaa.gov/~cjs/
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