Vertex pointer not updated on graph filtering

graph-tool
1

Hi together!

I just noticed that vertices that had been saved within an external list are not being updated when filtering the graph:

G.set_edge_filter( G.edge_properties[ 'e_isbus'], inverted=True)
G.set_vertex_filter(G.vertex_properties['v_isbus'], inverted=True)

print( [ int(n) for n in node.all_neighbors() ] )

[101, 22, 265, 496, 518, 22, 265, 496, 101, 518]

print( [ int(n) for n in G.vertex( int(node) ).all_neighbors() ] )

[101, 22, 265, 22, 265, 101]

Did I miss something or is this a bug?

Thanks a lot for any ideas!

Stephan

attachment.html (1.17 KB)

2

I don't view this as a bug. Vertex descriptors are supposed to be
ephemeral objects that you create in an ad hoc way. For performance
reasons they keep a direct pointer to the graph view that created them.
If you want to store vertices and look them up, it's better just to
store their index, and get a descriptor at the time you need it.

3

Ah, thank you very much for the clarification!

I'm gonna do some testing on that tomorrow.

Maybe you could add that piece of information to the documentation.

Esp. "they keep a direct pointer to the graph view that created them"
Best regards,
Stephan