% Author: Richard Groff
% Compute the Plucker coordinates of the line defined by points x and y
% in homogeneous form (i.e. a four vector)

function p=plucker(x,y);
p(1) = x(1)*y(2)-x(2)*y(1);
p(2) = x(1)*y(3)-x(3)*y(1);
p(3) = x(1)*y(4)-x(4)*y(1);
p(4) = x(3)*y(4)-x(4)*y(3);
p(5) = x(4)*y(2)-x(2)*y(4);
p(6) = x(2)*y(3)-x(3)*y(2); 