>A a4Kctj|}tj||}|j|}|j|}||z ||z zS)a~Returns the N-cut cost of a bi-partition of a graph. Parameters ---------- cut : ndarray The mask for the nodes in the graph. Nodes corresponding to a `True` value are in one set. D : csc_matrix The diagonal matrix of the graph. W : csc_matrix The weight matrix of the graph. Returns ------- cost : float The cost of performing the N-cut. References ---------- .. [1] Normalized Cuts and Image Segmentation, Jianbo Shi and Jitendra Malik, IEEE Transactions on Pattern Analysis and Machine Intelligence, Page 889, Equation 2. )nparrayrcut_costdatar )cutrrrassoc_aassoc_bs r ncut_costr sh0 (3--C a((HfSkooGfcTl  G w 8g#5 66r) networkxr numpyrscipyrrrrrrr%si2 7 7 7 7 7r