OBLATESURFACEAREA Approximated surface area of an oblate ellipsoid. S = oblateSurfaceArea(R1,R2) Example oblateSurfaceArea See also geom3d, ellipsoidSurfaceArea, prolateSurfaceArea
0001 function S = oblateSurfaceArea(elli, varargin) 0002 %OBLATESURFACEAREA Approximated surface area of an oblate ellipsoid. 0003 % 0004 % S = oblateSurfaceArea(R1,R2) 0005 % 0006 % Example 0007 % oblateSurfaceArea 0008 % 0009 % See also 0010 % geom3d, ellipsoidSurfaceArea, prolateSurfaceArea 0011 % 0012 0013 % ------ 0014 % Author: David Legland 0015 % e-mail: david.legland@grignon.inra.fr 0016 % Created: 2015-07-03, using Matlab 7.9.0.529 (R2009b) 0017 % Copyright 2015 INRA - Cepia Software Platform. 0018 0019 %% Parse input argument 0020 0021 if size(elli, 2) == 7 0022 R1 = elli(:, 4); 0023 R2 = elli(:, 5); 0024 0025 elseif size(elli, 2) == 1 && ~isempty(varargin) 0026 R1 = elli(:, 1); 0027 R2 = varargin{1}; 0028 end 0029 0030 assert(R1 < R2, 'First radius must be smaller than second radius'); 0031 0032 % surface theorique d'un ellipsoide oblate 0033 % cf http://fr.wikipedia.org/wiki/Ellipso%C3%AFde_de_r%C3%A9volution 0034 e = sqrt(R2.^2 - R1.^2) ./ R2; 0035 S = 2 * pi * R2.^2 + pi * R1.^2 * log((1 + e) ./ (1 - e)) ./ e;