f_sc

Second smallest eigenvalue of Normalised Laplacian and difference to 3rd smallest
[F, EIGENGAP] = F_SC(V, X, PARS)

 Inputs:
    (V): Projection matrix (vector storing matrix column-wise)
    (X): Data matrix
    (PARS): parameter struct containing 
        (sigma): scaling parameter for Gaussian kernel
        (weights): weights of micro-clusters (if not used should be empty)
        (beta), (delta): parameters of similarity transform function
        (omega): penalty term used to ensure orthonormality of (v)

 Output: 
    (F): Second smallest eigenvalue of Normalised Laplacian
    (EIGENGAP): Difference between 3rd and 2nd smallest eigenvalues