Method value can be ''positive'' only if all edge weights are nonnegative. Distance must be a real numeric scalar. Distance must be a real, nonnegative numeric scalar. No value given for {0}. Graph edge weights must be nonnegative. Shortest path distance undefined because the graph contains a negative cycle of length {0} (nodes {1}). Source must specify one node. Direction value must be ''outgoing'' or ''incoming''. Parameter name must be ''Direction'' or ''Method''. Parameter name must be ''Method''. Method value must be ''auto'', ''unweighted'', ''positive'', or ''mixed''. Method value must be ''auto'', ''unweighted'', or ''positive''.