Hi, I am a newbie in using boost libraries and template programming, and I try to get familiar with the graph library at the moment. My first problem is, that I want to create subgrahps in "sub-functions" and create the whole graph out of these subgraphs in the calling function. I tried to create the subgraph in the calling function and pass it to the sub-function, but then, the new vertices were added to the root-graph and not to the subgraph. I solved this in the calling-function with adding all the new vertices and their edges again to the subgraph. Is there a better way to do that? My second problem is just as mentioned in the subject line. How to use boost::write_graphviz to print out subgraphs? It works for "normal" graphs but not for subgraphs. I hope this is the right place to ask these questions. Thanks for your answers. Lisa __________________________________________________ Do You Yahoo!? Sie sind Spam leid? Yahoo! Mail verfügt über einen herausragenden Schutz gegen Massenmails. http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Sie sind Spam leid? Yahoo! Mail verfügt über einen herausragenden Schutz gegen Massenmails. http://mail.yahoo.com