Geometry library for matlab. Performs geometric computations on points, lines, circles, polygons...
function trans = createHomothecy(point, ratio)
%CREATEHOMOTHECY Create the the 3x3 matrix of an homothetic transform
% TRANS = createHomothecy(POINT, K);
% POINT is the center of the homothecy, K is its factor.
% See also:
% transforms2d, transformPoint, createTranslation
% author : David Legland
% INRA - TPV URPOI - BIA IMASTE
% created the 20/01/2005.
% 22/04/2009: rename as createHomothecy
% extract coordinate of center
x0 = point(:,1);
y0 = point(:,2);
% compute coefficients of the matrix
m00 = ratio;
m01 = 0;
m02 = x0*(1-ratio);
m10 = 0;
m11 = ratio;
m12 = y0*(1-ratio);
% create transformation
trans = [m00 m01 m02; m10 m11 m12; 0 0 1];