I want to write a program in python that simulates a queueing system.
I have a G/M/1 queue. For the service time, I chose expovariate(1.0). For the interarrival time, I chose gammavariate(2.0,a). I change a to different values to make a curve about the arrival rate. But what is the arrival rate of that distribution?
I know that the arrival rate $\lambda$ equals $\frac{1}{E[A]}$, with A the interarrival time. However what is the mean of this interarrival time, if it is a gamma distribution like gammavariate(2,a) in python?