Yes, but the second can be written as get.vertex.attribute(g, attr, id), which is a lot more readable and it i also slightly faster.
Gabor On Thu, Apr 10, 2014 at 5:35 PM, Bob Pap <[email protected]> wrote: > Many thanks dear Gabor. I think the following two should do (equivalent?) > > 1. function(g,id="identifierXX",attr="betweeness") { > get.vertex.attribute(g,attr)[which(V(g)$name==id)] > } > > 2. function(g,id="identifierXX",attr="betweeness") { > get.vertex.attribute(g,attr,V(g)[which(V(g)$name==id)]) > } > > > Kindly, > Bob Pap > > > On 10 April 2014 18:45, Gábor Csárdi <[email protected]> wrote: > >> On Thu, Apr 10, 2014 at 12:31 PM, Bob Pap <[email protected]> wrote: >> >>> Dear all, >>> >>> Unaware of any method for dealing with multigraphs (in my case a family >>> of graphs "g" indexed by time), I handle these by creating a list, indexed >>> by the time period, say "Mygraphs", where Mygraphs[["2014-01-01"]] returns >>> graph g as it was in 2014-01-01. >>> >>> I face the need to extract a combination of attributes from the series >>> (in the example below the vertex's "id" and "betweeness", ordered by the >>> index of Mygraphs), I do so for example as follows: >>> >>> sapply( >>> Mygraphs, >>> function(g,id="identifierXX",attr="betweeness") { >>> get.vertex.attribute(induced.subgraph(g, which(V(g)$name==id)),attr) >>> } >>> ) >>> >>> I cannot help to think that the use of induced.subgraph could be >>> obviated by specifying the 2 dimensions (id and attr) at once in the >>> extraction, but I how would I restrict get.vertex.attribute to only return >>> the value for vertex "identifierXX" only? >>> >> >> See the 'index' argument of 'get.vertex.attribute'. >> http://igraph.org/r/doc/attributes.html >> >> Gabor >> >> >>> >>> Any guidance would be appreciated. >>> Kindly, >>> Bob Pap >>> >>> _______________________________________________ >>> igraph-help mailing list >>> [email protected] >>> https://lists.nongnu.org/mailman/listinfo/igraph-help >>> >>> >> >> _______________________________________________ >> igraph-help mailing list >> [email protected] >> https://lists.nongnu.org/mailman/listinfo/igraph-help >> >> > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help > >
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