R help - Jul 2008 - Calculating Betweenness - Efficiency problem

Hello,

I am calculating 'Betweenness' of a large network using R. Currently, I
have the node-node information (City1-City2) in an excel file, present in two
columns where column A has City1 and column B has City2 that city1 is connected
to. These are the steps that I go through to calculate betweenness of my
network.

a) Convert the City1-City2 (text) into Number1-Number2 in the excel file where
every unique city has a unique number.
b) Paste all the city-city information separated by comma into c(...) in the R
GUI to obtain the corresponding vectors. As you can imagine this copy-paste
operation takes a long time. Example: c(1,3,1,5,2,4,2,5). Just fyi, I have a
text file that contains all nodes separated by comma based on the appropriate
link information.
c) Then, I create a graph file with the above vector.
d) I use the graph file to calculate betweenness of my network.

I am sure there must be a better, more efficient way to calculate betweenness.
Ideally, I would like to just have the City1 - City2 (link) information in two
columns in an excel file and calculate the betweenness from that file directly.

Please provide an optimal solution for this problem. I appreciate your time and
help.

Thanks,
Senthil

	[[alternative HTML version deleted]]

It would seem that you can output the initial file from EXCEL, read it
into R with 'read.csv' and then use 'factor' to convert the
characters
for City1 and City2 to the numbers that you want to use.  Have you
tried this approach?

On Fri, Jul 18, 2008 at 3:51 PM, Senthil Purushothaman
<spurushothaman at lnxresearch.com> wrote:
> Hello,
>
> I am calculating 'Betweenness' of a large network using R.
Currently, I have the node-node information (City1-City2) in an excel file,
present in two columns where column A has City1 and column B has City2 that
city1 is connected to. These are the steps that I go through to calculate
betweenness of my network.
>
> a) Convert the City1-City2 (text) into Number1-Number2 in the excel file
where every unique city has a unique number.
> b) Paste all the city-city information separated by comma into c(...) in
the R GUI to obtain the corresponding vectors. As you can imagine this
copy-paste operation takes a long time. Example: c(1,3,1,5,2,4,2,5). Just fyi, I
have a text file that contains all nodes separated by comma based on the
appropriate link information.
> c) Then, I create a graph file with the above vector.
> d) I use the graph file to calculate betweenness of my network.
>
> I am sure there must be a better, more efficient way to calculate
betweenness. Ideally, I would like to just have the City1 - City2 (link)
information in two columns in an excel file and calculate the betweenness from
that file directly.
>
> Please provide an optimal solution for this problem. I appreciate your time
and help.
>
> Thanks,
> Senthil
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?