Embed the points using kernel PCA of the affinity matrix

        Parameters
        ----------
        n:      int
                The number of dimensions

def kpca_embedding(self, n):
        """
        Embed the points using kernel PCA of the affinity matrix

        Parameters
        ----------
        n:      int
                The number of dimensions
        """
        return self.dm.embedding(n, 'kpca', affinity_matrix=self._affinity)