[igraph] R igraph: vertex IDs starting at 1 now?

[Narayanan, Manikandan (NIH/NIAID) [E]]

Hi,

  Vertex IDs used to start at 0 (as described here: http://igraph.wikidot.com/r-traps ). In latest version (R igraph 0.6.5), I see them starting from 1 as shown in code below.

 

  Could you please confirm if this change is intentional?

 

 

#Code

> g <- graph.atlas(1000)

> V(g)[0]

 

# Output in igraph_0.5.5-4

Vertex sequence:

[1] 0

 

# Output in igraph_0.6.5-1

Vertex sequence:

numeric(0)

 

 

  I tried looking in the release notes but couldn’t find anything about this. If this change is not intentional, I would like to debug what is going on with my installation of the latest version.

 

 

Thanks,

Mani