[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

[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 (e.g.,

[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 (e.g.,