Calculus

  • Jacobian Matrix

    Suppose \(f: \R^n \to \R^m\), with input \(x \in \R^n\) and output \(y \in \R^m\): \[ f = \begin{cases} y_1 = f_1(x_1, x_2, ..., x_n) \\ y_2 = f_2(x_1, x_2, .

  • Spherical Coordinates

    The conversion between the 2-d Cartesian coordinate system and the 2-d polar coordinate system can be extended to a higher dimension, say \(k\)-d. In \(k\)-d case, their conversion can be

  • Lipschitz Continuity

    For a continuous mapping \(f\), it is \(K\)-Lipschitz continuous if there exists a number \(K\) such that \(\forall x,y \in \dom(f)\) \[ ||f(x) - f(y)|| \le K||x - y|| \] If the gradient of \(f\) is \(K\)-Lipschitz continuous, we further say \(f\) is \(K\)-smooth.