Dear Jani, I tried to install Rgraphviz using your tips: https://stat.ethz.ch/pipermail/bioconductor/2004-December/007062.html But I got following error messages: [root at analysis Rpack]# R CMD INSTALL Rgraphviz_1.5.10.tar.gz * Installing *source* package 'Rgraphviz' ... checking for graphviz... checking for dotneato-config... not found failed configure: error: please specify a valid path to 'dotneato-config' version >= 1.12 using --with-graphviz=DIR ERROR: configuration failed for package 'Rgraphviz' Unlike Liviu's case in above URL of yours, I couldn't find dotneato-config in /usr/bin/ directory. Do you think this is because of the version difference in graphviz (mine is 2.4, the most current version) or I have done something wrong (which is more likely)? Thank you. Jihoon Kim