beziercoeff

function coeff=beziercoeff(x,y)
bx=3*(x(2)-x(1));
by=3*(y(2)-y(1));
cx=3*(x(3)-x(2))-bx;
cy=3*(y(3)-y(2))-by;
dx=x(4)-x(1)-bx-cx;
dy=y(4)-y(1)-by-cy;
coeff=zeros(2,4);
coeff(1,:)=[x(1),bx,cx,dx];
coeff(2,:)=[y(1),by,cy,dy];