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   Calculates an ellipsoid given the ellipsoid matrix, semimajor axes, the unit 
   vectors along the axes and the number of patches
   It is similar to the sphere function from Matlab
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   Form:
   [x, y, z] = Ellipsoid( s, u, n )
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   Inputs
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   s         (3,1)      semi-major axes
   u         (3,3)      principal axes
   n         (1)        number of patches  

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   Outputs
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   x         (n+1,n+1)  x-component of vertices of patch
   y         (n+1,n+1)  y-component of vertices of patch
   z         (n+1,n+1)  z-component of vertices of patch

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