Creates an gamma distributed waiting time
an external pointer
the shape parameter of the gamma distribution
the scale parameter of the gamma distribution, i.e., 1/rate
This function creates an C++ object of type ExpWaitingTime. It can be passed to addTransition or Simulation$addTransition to specify the waiting time for a transition. As a C++ object, it is faster than using an R function to generate waiting times because there is no need to call an R function from C++.