Senthil, sending a 12Mb file to the list is not a good idea. I've run the code in my previous email without any problem, so you need to be a bit more specific about what went wrong for you.
This is what I get: > library(igraph) > tab <- read.csv("/tmp/Test.csv") > dim(tab) [1] 304711 2 > length(unique(tab)) [1] 2 > g <- graph.data.frame(tab) > summary(g) Vertices: 48072 Edges: 304711 Directed: TRUE No graph attributes. Vertex attributes: name. No edge attributes. > system.time(bet <- betweenness(g)) user system elapsed 661.180 0.098 661.716 > length(bet) [1] 48072 > bet <- data.frame(city=V(g)$name, betweenness=bet) > dim(bet) [1] 48072 2 Best, Gabor On Tue, Jul 22, 2008 at 11:58:37AM -0700, Senthil Purushothaman wrote: > Dear Gabor, > Thank you very much for the insights. I have been using the igraph > package for my computations. But I did not know about > graph.data.frame(). Thanks again for that. So I did run my data using > the steps you had provided. Weirdly, even though the .csv file has > approximately 300,000 records (remember that the file gets truncated to > 65536 rows when opened in Excel 2003), not all of them are pulled in > during the operation and the final betweenness list contains only ~1000+ > records but it should be tens of thousands. > > I know that you are a busy person. This problem seems to be a very > different challenge. I am attaching the Test.csv file for your > experiments. Thank you very much again. > > Best regards, > Senthil > (909) 267-0799 > > -----Original Message----- > From: Gabor Csardi [mailto:[EMAIL PROTECTED] > Sent: Monday, July 21, 2008 1:57 AM > To: Senthil Purushothaman > Cc: jim holtman; r-help@r-project.org > Subject: Re: [R] Calculating Betweenness - Efficiency problem > > Senthil, > > you can try the 'igraph' package. Export your two-column Excel file > as a .csv, use 'read.csv' to read that into R, then 'graph.data.frame' > to create an igraph graph from it. Finally, call 'betweenness' on > the graph. It is really just three/four lines, something like this: > > tab <- read.csv(...) > g <- graph.data.frame(tab) > bet <- betweenness(g) > bet <- data.frame(city=V(g)$name, betweenness=bet) > > The last line creates a two column data frame with the betweenness > score of each city. > > Best, > Gabor [...] -- Csardi Gabor <[EMAIL PROTECTED]> UNIL DGM ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.