SailOrbitContours:

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   Create and draw sail orbit contours. 
   BetaFunction is a function computing sail loading, i.e.
      [angle,beta] = BetaFunction( x, z, arg1, arg2, ... )

   See also SampleOrbitContours.

   Since version 7.
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   Form:
   [c,h] = SailOrbitContours( BetaFunction, betaC, x, z, varargin )
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