qiskit/transpiler/coupling.py
def _compute_distance_matrix(self):
        """Compute the full distance matrix on pairs of nodes.

        The distance map self._dist_matrix is computed from the graph using
        all_pairs_shortest_path_length.
        """
        if not self.is_connected():
            raise CouplingError("coupling graph not connected")
        lengths = nx.all_pairs_shortest_path_length(self.graph.to_undirected(as_view=True))
        lengths = dict(lengths)
        size = len(lengths)
        cmap = np.zeros((size, size))
        for idx in range(size):
            cmap[idx, np.fromiter(lengths[idx].keys(), dtype=int)] = np.fromiter(
                lengths[idx].values(), dtype=int)
        self._dist_matrix = cmap
def _compute_distance_matrix(self):
        """Compute the full distance matrix on pairs of nodes.

        The distance map self._dist_matrix is computed from the graph using
        all_pairs_shortest_path_length.
        """
        if not self.is_connected():
            raise CouplingError("coupling graph not connected")
        lengths = nx.all_pairs_shortest_path_length(self.graph.to_undirected(as_view=True))
        lengths = dict(lengths)
        size = len(lengths)
        cmap = np.zeros((size, size))
        for idx in range(size):
            cmap[idx, np.fromiter(lengths[idx].keys(), dtype=int)] = np.fromiter(
                lengths[idx].values(), dtype=int)
        self._dist_matrix = cmap
Compute the full distance matrix on pairs of nodes.

        The distance map self._dist_matrix is computed from the graph using
        all_pairs_shortest_path_length.