[igraph] GraphML in R

[Matthew Walker]

Hi,

I was trying to get GraphML support for the R interface to iGraph.  I 
finally learnt that I must pass to configure the path I used to install 
libxml2.  This took me a wee while to figure out so I have written up a 
few lines on the wiki (http://igraph.wikidot.com/installation-issues) in 
case anyone else has the same desire.  I would love to know if this is 
the "correct" way to get iGraph to work with libxml2 as I was surprised 
that iGraph didn't just take the information offered by pkg-config.

While doing that however, I noticed that support for GMP was turned 
off.  Out of curiosity I installed GMP but it was still "off" no matter 
what options I passed to ./configure.  I looked at the configure.ac and 
it appears that the line "gmp_support=no" might be the cause.  Setting 
"gmp_support=yes" seems to work.  Is this "no" intentional?  What does 
GMP support offer anyway?

I then uninstalled igraph from R (using remove.package()) and then 
followed Gabor's instructions on how create an R package [1] however, 
despite all this, I still do not have GraphML support in R:
> library(igraph)
> read.graph("~/Desktop/example.graphml.xml", format="graphml")
Error in read.graph.graphml(file, ...) :
 At foreign-graphml.c:1033 : GraphML support is disabled, Unimplemented 
function call

Do you have any suggestions for what I am doing wrong?  I would greatly 
appreciate your help!

Thanks,

Matthew

[1] http://lists.gnu.org/archive/html/igraph-help/2007-04/msg00025.html