Axel, I really think that this need would probably be too specific to be including in as general a library as MASON.



Sean



On Aug 8, 2015, at 4:12 PM, Axel Kowald <[log in to unmask]> wrote:



> Hi Everybody,

> 

> this time I have a suggestion for a new feature for MASON and I wonder

> if others would also find it useful.

> 

> The point is that I find myself often with the problem to run a

> simulation until one or all of my agent types have reached a steady

> state. Basically I keep track of the number of my agents with a variable

> and then plot this variable while the simulation is running. I simply

> watch this plot and stop it manually whenever I have the feeling that a

> steady state is reached.   

> 

> But this seems to be a very non-reproducible and cumbersome way of doing it.

> Maybe this would be a job for the Schedule class of MASON ?

> If we are only interested in the total number of all agents Schedule has

> in principle all the information it needs (number of agents at each time

> step). Of course if there are different agent types and the all should

> reach equilibrium things might become more complicated. I'm not sure

> what the best way is to test if a variable that is subject to random

> fluctuations has reached a steady state. Some ideas would be

> 

> (1) take the last N values, calculate a linear regression line and

> compute the p-value that the slope is different from zero.

> (2) to avoid the arbitrary choice of N, one could also start with the

> last 2 points and calculate the p-value. If it is below a given

> threshold stop, if not repeat the calculation with the last 3 points,

> etc. until a p-value below the threshold is found or until all available

> points are used. This seems computationally very expensive, but it was

> just an idea.

> 

> Any comments?

> 

> Axel

>