WindPowerClass:

--------------------------------------------------------------------------
   Gives the wind power class

   Enter WindPowerClass for a demo

--------------------------------------------------------------------------
   Form:
   wind = WindPowerClass( class, height )
--------------------------------------------------------------------------

   ------
   Inputs
   ------
   class     (1,1) 1-7
   height    (1,1) 10m or 50m

   -------
   Outputs
   -------
   wind     (n,m)  Wind (lon,lat)

--------------------------------------------------------------------------
   Reference: http://www.nrel.gov/gis/wind.html
--------------------------------------------------------------------------