Simulating Migration in SimBit Software Program
In SimBit, no specific model is assumed as the user can very much chose for himself/herself what migration scenario to be simulated. The migration scenario can be set with the option --m (or equivalently with --DispMat).

There are four ways (what is called "Mode" in the manual) to indicate migration. 
 A, LSS, OnePatch, Island and LinearNormal.


A


This mode stands for "All". This mode allows the user to enter a matrix with the migration rate between any two patches. Any migration scenario including the ones achieved with the below modes can be achieved with A. The interest of the other modes is to simplify the user's life esp. when dealing with many patches. I rather recommend using the other modes when these apply.

LSS


This mode stands for "Linear Stepping Stones". It allows the user to set linear stepping stones with any number of stones and potential asymmetry.

OnePatch


This is the default. It means no migration scenario apply as there is only one patch (or one deme if you prefer)

Island


This is a classical island model. The user must input the probability of not migrating.

LinearNormal


This is just like a linear stepping stone model except that the dispersal kernel follows a normal distribution.



Note also that the migration scenario (as well as the number of patches) is a time specific argument and therefore it can vary through time at will. You can have a look at the manual for more information.

Note that I have been working quite a lot on new versions that I have not put online yet, mainly because I was too lazy to rewrite the manual! The last version online is 3.69 but I am currently working on version 3.139! I will upload a more recent version in the coming week(s). Most notable improvement with the new version include:


Easier user interface; no need for all these quotation marks. Migration scenario will be given by the user as forward migration while it currently is backward migration which is a little less intuitive for the user.
More freedom on demography.
Possibility to simulate several species interaction with ecological relationships. One can simulate a whole ecosystem!