multiclass.py 文件源码

def _build_graph(self):
        """Compute the graph Laplacian."""

        # Graph sparsification
        if self.sparsify == 'epsilonNN':
            self.A_           = radius_neighbors_graph(self.X_, self.radius, include_self=False)
        else:
            Q                 = kneighbors_graph(
                self.X_,
                self.n_neighbors,
                include_self  = False
            ).astype(np.bool)

            if self.sparsify   == 'kNN':
                self.A_       = (Q + Q.T).astype(np.float64)
            elif self.sparsify == 'MkNN':
                self.A_       = (Q.multiply(Q.T)).astype(np.float64)

        # Edge re-weighting
        if self.reweight == 'rbf':
            W                 = rbf_kernel(self.X_, gamma=self.t)
            self.A_           = self.A_.multiply(W)

        return sp.csgraph.laplacian(self.A_, normed=self.normed)