Re: [igraph] Plotting a signed and directed graph

[Tom Backer Johnsen]

Gabor:

Your example was very nice, but when reading the graph it failed.  I 
suspect the error is in read.graph, but as far as I can see from the 
documentation, there are no arguments to tell the function that the 
graph is signe either.  I used the following commands in R:

library(igraph)
g <- read.graph (file="First.net", format="pajek")
g <- as.directed (g)
E(g)$curved <- is.mutual(g)
# -1 edges are dashed
E(g)$lty <- ifelse( E(g)$sign > 0, 1, 2)
# A nice layout
coords <- layout.fruchterman.reingold(g)
plot(g, layout=coords)

And the First.net file looks like this:

*NETWORK First.net; 14.04.2009 / 09:46:56
*Vertices 10
1 "S65"
2 "S29"
3 "S04"
4 "S75"
5 "S24"
6 "S81"
7 "S51"
8 "S78"
9 "S86"
10 "S39"
*Matrix
 0 0 0 0 0 1 0 0 0 -1
 0 0 1 1 0 1 1 0 1 0
 -1 0 0 1 0 0 1 0 1 0
 -1 1 0 0 1 1 1 0 1 0
 0 1 0 1 0 0 0 0 -1 -1
 1 -1 0 0 0 0 0 1 0 0
 0 -1 1 1 0 -1 0 0 1 0
 0 0 1 1 0 1 -1 0 1 1
 0 0 0 0 0 0 0 0 0 -1
 1 1 1 1 1 1 1 1 1 0

Tom


Tom Backer Johnsen wrote:
> Thanks for the detailed response!  And fast as well.  I'll look into it.
>
> Tom
>
> Gábor Csárdi wrote:
> > Tom,
> >
> > it is possible, with 0.5.2 or later versions. (Because of the curved
> > edges.) 0.5.2 will be on CRAN at any time, in the meanwhile it is
> > here:
> >
> > http://cneurocvs.rmki.kfki.hu/igraph/download/igraph_0.5.2.tar.gz
> > http://cneurocvs.rmki.kfki.hu/igraph/download/igraph_0.5.2.zip
> >
> > The latter is for windows. Here is how to do it:
> >
> > library(igraph)
> >
> > # just to always get the same nice picture
> > set.seed(123)
> >
> > # a small directed random graph to test
> > g <- random.graph.game(10, 20, type="gnm", directed=TRUE)
> >
> > # signs are random, too
> > E(g)$sign <- sample( c(-1,1), ecount(g), replace=TRUE)
> >
> > # mutual edges are curved
> > E(g)$curved <- is.mutual(g)
> >
> > # -1 edges are dashed
> > E(g)$lty <- ifelse( E(g)$sign > 0, 1, 2)
> >
> > # A nice layout
> > coords <- layout.fruchterman.reingold(g)
> >
> > # And the plot
> > plot(g, layout=coords)
> >
> > Best,
> > Gabor
> >
> > On Tue, Apr 14, 2009 at 10:43 AM, Tom Backer Johnsen
> > <address@hidden> wrote:
> > > Gentlepersons:
> > >
> > > I would like to obtain a plot of a signed and directed graph.  The 
> > > graph is
> > > small, 10 nodes or vertices.  Since the graph is directed, I would 
> > > like to
> > > have a curved arrow if there are arcs in both directions, with 
> > > continuous
> > > leines and dashed for the negative ones. After reading the graph 
> > > (containing
> > > -1's zeroes, and +1's) I see that I can plot a directed graph using g 
> > > <- as
> > > directed (g) and then plot (g).
> > >
> > > Is this possible?
> > >
> > > Tom
> > >
> > >
> > >
> > > _______________________________________________
> > > igraph-help mailing list
> > > address@hidden
> > > http://lists.nongnu.org/mailman/listinfo/igraph-help


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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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| Email : address@hidden    URL : http://www.galton.uib.no/ |
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