Convert quadratics from Homogeneous to Center form and back.
This zip file contains 2 functions to transform generic (nD) quadratic hyper-surfaces from homogeneous form (that is [x' 1]E[x;1]=0) to center form (that is (x'-c')inv(Q)(x-c)=1, which is used for example in the ellipsoidal toolbox).
Examples: % zero-centered ellipse of semiaxes 1 and 2 % center to homogeneous form: E=c2h(diag([1 4]),[0 0]') % homogeneous to center form: [Q,c]=h2c(E)