[ITK] Determinism & Registration v4

[Timothee Evain]

Hi everyone,

A small question about the registration v4 framework:
Is it possible to get a determinist pipeline ? 
I use the Mattes mutual information combined with the Regular step gradient descent and my problem is that each run produce a different parameter set.
The deviation is really small, but I expected to see same results with same inputs. 
I was testing with the REGULAR sampling strategy at first, but there is a random perturbation of the point picking in the code, so I tried with dense sampling, but here again, the results are varying. 
Is that an expected behavior ? 

Tim