Re: Reference to Latitude

[Lynn deWitt <ldewitt@xxxxxxxxxxxxxxxxxxxx>]

Bruce,
  This is one way:

yes?set data u1000a-feb98.nc
yes? let lat=y[gy=uwnd]
yes?!see what you've got:
yes? list lat
yes?!convert degrees to radians
yes? let degtorad=3.14159/180
yes? let lat_in_radians = lat * degtorad

let wca=((VWND[d=2,x=@SHF:1] -
VWND[d=2,x=@SHF:-1])/(2*2.77875e05*cos(lat_in_radians)))

Watch out for division by zero at poles!  (you may have to set your 
region to avoid this)

Lynn



> Ferreters! 
> In an expression like below, how would I extract and
> use the latitude of the current gridpoint (in place of
> "LAT"?
>
> let wca=((VWND[d=2,x=@SHF:1] -
> VWND[d=2,x=@SHF:-1])/(2*2.77875e05*cos(LAT)))
>
> The data I'm using is COARDS convention netCDF data
> (from CDC) with lon and lat defined within.
>
> Any assistance would be appreciated!
>
> Bruce
>
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--------------------------------------------
Lynn deWitt

ldewitt@pfeg.noaa.gov

Pacific Fisheries Environmental Laboratories
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