private static void CheckSVD(Matrix3d H, double threshold)
{
//check : H = U * EV * VT
Matrix3d EVMat = new Matrix3d();
EVMat = EVMat.FromVector(EV);
//check
// EV * VT
Matrix3d test = Matrix3d.Mult(EVMat, VT);
// U * EV * VT
test = Matrix3d.Mult(U, test);
test.CompareMatrices(H, threshold);
}