There seem to be two different “Graph” commands, although they have the same name.
GraphQ does not recognize all graphs. What shall I load in which sequence, if I want to use
some commands from graphutilities and from combinatorica? Command AdjacencyMatrix
shows the same problem.
I think that it is a little bit of a problem to use functionality from both graphutilities and combinatorica at the same time. As the error message says combinatorica is conflicting with the built-in functionality.
It is important that you load “CleanSlate”, before (!) you load Combinatorica. After that you can (in theory) load and unload Combinatorica functionality. The notebook is attached as well. This is not a good solution to your problem, but it might be a first step.
you could also call any conflicting or shadowing symbols by their full names, that is, including the name of their context:
Combinatorica`Graph
is not the same as
System`Graph
as you can see by evaluating their respective usage messages:
?Combinatorica`Graph
?System`Graph
I admit that this is a bit cumbersome because of the additional typing work, but it will allow you to access functions of the same name coming from different packages in a controlled way.