What does static mean? Constant at, say 2? This is already supported.
What does dynamic selection mean?

@mchantry Updated the description

I like the idea of dynamic selection of increments and I was also wondering if this could be done by steps as well as by epochs? For example at step 1000, do roll 2, at step 10000, do roll 10.
Also I think this would avoid the issue of if you wanted to do rollout within epochs as you could then define it by steps instead

I agree with @mc4117. Some models show a better performance when trained for longer on 2-steps and only some iterations on longer rollout steps. |
I wonder, however, if that could not be solved by limiting the number of batches per epoch and provide a list of rollout lengths, e.g. [2,2,2,2,2,2,2,2,3,4,5,6,...].

I like @mc4117 suggestion regarding supporting rollout by steps. I think this probably would make things easier if, in the future, we want to automate the training so that the 6-hour and the rollout steps are executed one after the other.

Moving to a discussion (to try it out)
ecmwf/anemoi-training#148