GraphViz: Windows PATH not set with new installer, issue when calling from R

Question

In an R library, I am using the dot program (from GraphViz) to produce some graphics (usually in png format). dot is a usual executable and I execute i

Answer 1

You have a valid concern, which is why we tried to alter the PATH in previous releases. First, yes, we will probably keep C:\Program Files (x86)\Graphviz(VersionNumber) as the default installation path. Second, if anyone can tell us how to alter the PATH safely at install time, we would appreciate it. Another possibility is to have the installation process set a Graphviz specific variable like GVPATH that records the directory containing dot.

Answer 2

We decided not to set PATH during installation. We had a lot of trouble doing this in a portable way, given our limited knowledge of Windows in its many forms. The huge downside of getting it wrong is that you trash some poor "not computer expert"'s PATH and they can't recover. We made a note to this effect on the Windows download page for Graphviz. I agree about setting .Rprofile. At least you limit the damage if something goes wrong.