function M = mkm(X,Y,Z,xim,yim)
  A = zeros(2*length(X),12);

  for i = 1:length(X)
    A(2*i-1,:) = [X(i) Y(i) Z(i) 1 0 0 0 0 -xim(i)*X(i) -xim(i)*Y(i) -xim(i)*Z(i) -xim(i) ];
    A(2*i,:) = [0 0 0 0 X(i) Y(i) Z(i) 1 -yim(i)*X(i) -yim(i)*Y(i) -yim(i)*Z(i) -yim(i) ];
  end
  
  [U S V] = svd(A);
  t = V(:,12); % closest singular value is last
  M = zeros(3,4);
  M(1,:) = t(1:4)';
  M(2,:) = t(5:8)';
  M(3,:) = t(9:12)';