f_df_ncut

Function value and derivative of minimum normalised cut projection index
[F,DF] = F_DF_NCUT(V, X, PARS)

 Inputs:
    (V): Projection vector
    (X): N-by-D Data matrix
    (PARS): parameter struct containing 
        (sigma) Scaling parameter for Laplace kernel
        (minsize): minimum cluster size

 Output: 
    (F): Value of normalised cut projection index
    (DF): derivative of (F) w.r.t. projection vector (V)