EllSphereGeomFact

 Returns geometrical factors associated with a given sphere (for which a=b=c)

 Parameters:
 - a: scalar or row vectors [1 x G]
      radius
 - sOptions: string (optional)
           if 'L', only L_1 is returned
           if 'All' (default), then all properties are returned
 Returns:
 - stEllGeom: structure with fields, all of size [1 x G]
 stEllGeom.a for future reference
 stEllGeom.S: surface area (in squared units of a, b, and c)
 stEllGeom.type: ='Sphere' (type of ellipsoid)
 stEllGeom.L1: Geometrical factor
 stEllGeom.exix2ave: <|e_xi . e_x|^2>
 stEllGeom.exix4ave: <|e_xi . e_x|^4>
 stEllGeom.exix2y2ave: <|e_xi . e_x|^2 |e_xi . e_y|^2>

 This file is part of the SPlaC v1.0 package (copyright 2008)
 Check the README file for further information

0001 if nargin<4, sOption='All'; end
0002 
0003 stEllGeom.a=a;
0004 stEllGeom.type='Sphere'; % for reference
0005 
0006 zeroa=0*a; % zero vector, same size as a
0007 
0008 stEllGeom.h=1+zeroa; % aspect ratio
0009 stEllGeom.e=zeroa; % eccentricity
0010 
0011 % surface area
0012 stEllGeom.S=4*pi*a.^2;
0013 
0014 % geometrical factor
0015 stEllGeom.L1=1/3 + zeroa;
0016 
0017 if ~strcmpi(sOption,'L') % returns other geometrical averages
0018 
0019     stEllGeom.exix2ave=1/3+zeroa; 
0020     stEllGeom.exix4ave=1/5+zeroa;
0021     stEllGeom.exix2y2ave=1/15+zeroa;
0022 end
0023 
0024 
0025 
0026