ellipseArea

ELLIPSEAREA Area of an ellipse.

   AREA = ellipseArea(ELLI)
   Computes he area of the ellipse ELLI, by taking the product of the semi
   axis length and multiplying by PI:
      AREA = PI * RA * RB 

   Example
     % area of a simple ellipse
     elli =  [50 50   40 20  30];
     ellipseArea(elli)
     ans =
        2.5133e+03
     % when scaling by K, area is scaled by K^2:
     transfo = createScaling(.2);
     elliT = transformEllipse(elli, transfo);
     ellipseArea(elliT)
     ans =
       100.5310


   See also
     ellipses2d, ellipsePerimeter, ellipseToPolygon

0001 function area = ellipseArea(elli)
0002 %ELLIPSEAREA Area of an ellipse.
0003 %
0004 %   AREA = ellipseArea(ELLI)
0005 %   Computes he area of the ellipse ELLI, by taking the product of the semi
0006 %   axis length and multiplying by PI:
0007 %      AREA = PI * RA * RB
0008 %
0009 %   Example
0010 %     % area of a simple ellipse
0011 %     elli =  [50 50   40 20  30];
0012 %     ellipseArea(elli)
0013 %     ans =
0014 %        2.5133e+03
0015 %     % when scaling by K, area is scaled by K^2:
0016 %     transfo = createScaling(.2);
0017 %     elliT = transformEllipse(elli, transfo);
0018 %     ellipseArea(elliT)
0019 %     ans =
0020 %       100.5310
0021 %
0022 %
0023 %   See also
0024 %     ellipses2d, ellipsePerimeter, ellipseToPolygon
0025 %
0026 
0027 % ------
0028 % Author: David Legland
0029 % E-mail: david.legland@inrae.fr
0030 % Created: 2022-09-09, using Matlab 9.12.0.1884302 (R2022a)
0031 % Copyright 2022-2024 INRAE - BIA Research Unit - BIBS Platform (Nantes)
0032 
0033 area = elli(:,3) .* elli(:,4) * pi;