Clears a graph object (resets all its data streams). See also simHandleGraph.
simInt simResetGraph(simInt graphHandle)
graphHandle: handle of the graph object or sim_handle_all or sim_handle_all_except_explicit. (sim_handle_all will reset all graph objects, while sim_handle_all_except_explicit will only reset those that are not marked as "explicit handling")
C return value
-1 if operation was not successful. In a future release, a more differentiated return value might be available