[igraph] Vertex id consistency in delete.vertices and subgraph

[Andrew Conway]

From the documentation for the R version of igraph it is noted that after manipulating a graph via the delete.vertices or subgraph functions, "The ids of the vertices will change in the subgraph of course since these are always consecutive."

I am curious as to the motivation for this implementation?  Often, it is much more useful to keep vertex ID's consistent after these operations, as these ID's are often meaningful to the particular analysis being performed.  Is there a way to keep the IDs consistent after performing these manipulations?

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Drew Conway

Ph.D. Student

Department of Politics, New York University

address@hidden

http://www.drewconway.com/zia

@drewconway