[sage-devel] Re: updating the _pos dictionary for graphs

2008-11-05 Thread Jason Grout
Robert Miller wrote: > Jason, > >> Does anyone know if it is assumed that if the _pos dictionary in a graph >> is not None, then it contains each vertex as a key? It seems like it is >> assumed several places in the code (e.g., in the subgraph() function). >> However, _pos isn't updated properly

[sage-devel] Re: updating the _pos dictionary for graphs

2008-11-05 Thread Jason Grout
Robert Miller wrote: > Jason, > >> Does anyone know if it is assumed that if the _pos dictionary in a graph >> is not None, then it contains each vertex as a key? It seems like it is >> assumed several places in the code (e.g., in the subgraph() function). >> However, _pos isn't updated properly

[sage-devel] Re: updating the _pos dictionary for graphs

2008-11-05 Thread Robert Miller
Jason, > Does anyone know if it is assumed that if the _pos dictionary in a graph > is not None, then it contains each vertex as a key? It seems like it is > assumed several places in the code (e.g., in the subgraph() function). > However, _pos isn't updated properly (e.g., in the delete_vertex