Re: [igraph] Plotting a signed and directed graph

[Tom Backer Johnsen]

Gábor Csárdi wrote:
> On Tue, Apr 14, 2009 at 5:46 PM, Tom Backer Johnsen <address@hidden> wrote:
> [...]
> > As to documentation of the Pajek format, there are at least two examples of
> > valued and directed graphs in the book "Exploratory Social Network Analysis
> > with Pajek" by de Nooy, Mrvar, and Batagelj, Cambridge University Press.
> >  You will find the examples on pages 8 (valued) and 93 (valued and signed)
> > in that book.  Instead of representing the graph as a matrix as I did, the
> > command is *Arcs, followed by a list of the arcs, consisting of a sender (by
> > number from the first part of the file) the receiver (again by number) and
> > then the value.  The values are all positive on the one on page 8, and
> > signed on page 93.
>
> Yes, this format we support. (I believe.) I just haven't seen the
> signed matrix format so far.
>
> Have you already seen the signed matrix format somewhere else or it
> was created by Pajek?

Puh.  The answer to that might easily be no. I have no references at the 
moment.  I may simply have assumed that the signed and valued graph may 
be represented in matrix format.   So I may be on very thin ice there.
> Btw., yes I know that there are several examples for Pajek file
> formats, but this is not how you should _define_ a format. It would be
> much easier with a formal definition.

I agree.  The definitions I have is by example, not formally.  Anyhow, 
here is the graph I included in a previous reply in *Arcs format.  I'll 
try that one on igraph in a moment.

*NETWORK FirstA.net; 14.04.2009 / 18:07:12
*Vertices 10
1 "S65"
2 "S29"
3 "S04"
4 "S75"
5 "S24"
6 "S81"
7 "S51"
8 "S78"
9 "S86"
10 "S39"
*Arcs
1 6 1
1 10 -1
2 3 1
2 4 1
2 6 1
2 7 1
2 9 1
3 1 -1
3 4 1
3 7 1
3 9 1
4 1 -1
4 2 1
4 5 1
4 6 1
4 7 1
4 9 1
5 2 1
5 4 1
5 9 -1
5 10 -1
6 1 1
6 2 -1
6 8 1
7 2 -1
7 3 1
7 4 1
7 6 -1
7 9 1
8 3 1
8 4 1
8 6 1
8 7 -1
8 9 1
8 10 1
9 10 -1
10 1 1
10 2 1
10 3 1
10 4 1
10 5 1
10 6 1
10 7 1
10 8 1
10 9 1

Tom

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| Tom Backer Johnsen, Psychometrics Unit,  Faculty of Psychology |
| University of Bergen, Christies gt. 12, N-5015 Bergen,  NORWAY |
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