Hi David, please see the Vignette "A New Interface to Plot Graphs Using Rgraphviz" of the devel version of Rgraphviz. Section 5.2 deals with edge arrow shapes, and tee is one that is supported. You can also create custom shapes by providing a function. I forwarded this to the bioc mailing list in order for others to benefit. Florian On 03.04.2009, at 07:46, Jitao (David) Zhang wrote: > Hi Florian, > > I have a question about the Rgraphviz visualiazation: so far is > there a way to draw the arrow in 'tee' instead of 'normal' style? > That is, '--|' instead of '-->'. The former one is widely used to > represent inhibitory effect however I could not find how to draw it > with Rgraphviz. > > Thanks! > > -- > Cheers, > David