Comments on: Weighted Rich-club Effect: A more appropriate null model for scientific collaboration networks

By: Raj

Raj — Mon, 07 Mar 2011 16:57:01 +0000

Many thanks for the clarification.

By: Tore Opsahl

Tore Opsahl — Thu, 03 Mar 2011 13:44:54 +0000

Raj,

Thank you for taking an interest in my work.

The randomisation procedure is as you suggest and outlined in the two-mode diagram above; however, we do not seem to have the same interpretation of the term degree. In my opinion, degree is the number of connections or adjacent nodes. While this is straight forward in a one-mode network, in two-mode networks this can be connections to nodes (of the other node set) or nodes two-steps away from a node. I have chosen to use the former assumption (often referred to as a node’s two-mode degree) instead of the latter (often referred to as a node’s one-mode degree as this is the node’s degree if the network is projected).

I hope this clarifies the issue,

Tore

By: Raj

Raj — Thu, 03 Mar 2011 13:35:27 +0000

Nice Blog. Can you describe in detail the reshuffling procedure which maintain both the authors’ and papers’ degree. Say, A-B has written 2 papers, while C-D have written 1 paper. Then,
A-B
A-B
C-D
If this is reshuffled to say,
A-B
A-D
C-B
Then, the degree of A has changed.
Thanks for you time.

By: Tore Opsahl

Tore Opsahl — Sat, 30 Oct 2010 11:46:02 +0000

This works perfectly fine on my computer. Have you tried to install other packages? If this prblem persist, there might be something wrong with your R setup. If this is only an issue with igraph, then contact the authors behind that package.

Tore

By: Pral

Pral — Fri, 29 Oct 2010 16:43:24 +0000

Can u please tell me how to install R-igraph. I get an error:

install.packages(“igraph”): command not found

By: Tore Opsahl

Tore Opsahl — Thu, 19 Aug 2010 12:30:29 +0000

Samir,

This was due to a problem with the igraph-package. The guys behind that package (Gabor Csardi) have just submitted a new version of their R-package that should solve this issue. As soon as it has been approved by CRAN and disseminated across the servers, you should be able to get it by writing update.packages() in R.

Tore

By: Tore Opsahl

Tore Opsahl — Tue, 17 Aug 2010 14:55:47 +0000

Samir,

Thank you for taking an interest in my work, and tnet.

tnet requires that igraph is installed as this package does some of these computationally heavy stuff in C++ and tnet is solely written in R.

Did you install tnet using the install.packages(“tnet”)-command? If so, igraph should have automatiically been installed. Also, try to run update.packages() to see whether an update could sort the packages out. If none of these things work, please contact me offline.

Best,

Tore

By: Samir

Samir — Mon, 16 Aug 2010 22:22:44 +0000

Dear Tore,
thank you for the beautiful blog.

I installed R on my pc andI installed the package tnet.
If i compute your code, R give me an error:
“Loading required package: igraph
Error : .onLoad failed in loadNamespace() for ‘igraph’, details:
call: inDL(x, as.logical(local), as.logical(now), …)
error: unable to load shared library ‘C:/Users/ssuweis/Documents/R/win-library/2.11/igraph/libs/igraph.dll’:
LoadLibrary failure: The specified module could not be found.”

So I installed also the package “igraph” and I tried to load it, but a new error appear:

“Error: package/namespace load failed for ‘igraph’”

Of course I have set the directory in the folder where I have my “personal library”‘, so I cannot understand why I cannot load both tnet and igraph package.

I think it is a trivial problem that occurs to beginners in R like me, andI tried to google the latter error, but I did not find any useful suggestions..If you can help I really appreciate it!

Thanks and best

Samir