On Tue, Mar 20, 2012 at 2:20 PM, Charles Novaes de Santana <[email protected]> wrote: > Hi Simone, > > Considering you have the names of your vertices in a variable named > "vertices", in a very straightforward way you could do: > > v1<-which(vertices=="this"); > v2<-which(vertices=="that"); > g<-add.edges(g,c(v1,v2));
This is good, except that you need to subtract one, because vertices are numbered from zero. G. > So, the R function you are looking for is called "which". > > Surely there are other (more elegant) ways to do it, but that is the > one I remember now. > > All the best, > > Charles > > On Tue, Mar 20, 2012 at 6:59 PM, Simone Gabbriellini > <[email protected]> wrote: >> Dear List, >> >> sorry for this very basic question, but I am trying to select a vertex >> based on the value of an attribute. I forgot the R syntax, and I got >> lost trying to pick it up again... >> >> I would like to create an edge between two nodes for which I only know >> the value of the attribute, like: >> >> add.edges(g, c( the-ID-of-vertex-with-name=="this", >> the-ID-of-vertex-with-name=="that")) >> >> can you please advice? >> >> Best, >> Simone >> >> -- >> Dr. Simone Gabbriellini >> >> DigitalBrains srl >> Amministratore >> >> mobile: +39 3403975626 >> mail: [email protected] >> >> _______________________________________________ >> igraph-help mailing list >> [email protected] >> https://lists.nongnu.org/mailman/listinfo/igraph-help > > > > -- > Um axé! :) > > -- > Charles Novaes de Santana > http://www.imedea.uib-csic.es/~charles > PhD student - Global Change > Laboratorio Internacional de Cambio Global > Department of Global Change Research > Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB) > Calle Miquel Marques 21, 07190 > Esporles - Islas Baleares - España > > Office phone - +34 971 610 896 > Cell phone - +34 660 207 940 > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help -- Gabor Csardi <[email protected]> MTA KFKI RMKI _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
