feat: Optimisation

[toby-coleman]

Summary

Can we use Ray tune as an Optuna wrapper? This way we can access the Optuna algorithms without the need to develop a compute platform + storage database.

Example

No response

Alternatives

No response

[toby-coleman]

@chrisk314 as discussed, keen to get your thoughts on the following.

For the optimiser configuration, I'm intending to have something like:

plugboard:
  process:
    args:
      components:
      - type: my_package_my_components.A
        args:
          name: "a"
          iters: 10
      - type: my_package_my_components.C
        args:
          name: "c"
          my_arg: 0.1
  tune:
    objective: my_component.out_1
    mode: max
    num_samples: 100
    ...
    parameters:
    - name: my_param
       location: process.args.components.1.args.my_arg
       type: float
       min: 0
       max: 1

The optimiser code will look at the location of each parameter, pick trial values, then override the value at each location before building the process and running a trial on it.

What do you think of this as a user-experience? My concern is that setting locations like process.args.components.1.args.my_arg is a bit fiddly. An alternative I considered would be to modify the YAML parser to detect anchors, e.g.:

plugboard:
  process:
    args:
      components:
      - type: my_package_my_components.A
        args:
          name: "a"
          iters: 10
      - type: my_package_my_components.C
        args:
          name: "c"
          my_arg: &my_named_param 0.1  # Set anchor here
  tune:
    objective: my_component.out_1
    mode: max
    num_samples: 100
    ...
    parameters:
    - name: my_named_param  # Use name of anchor here
       type: float
       min: 0
       max: 1

Seems more user friendly, but anything like this ties us to the YAML parser for anything to do with optimisation.

Another alternative might be to have a simplified location syntax, e.g. something like components.c.my_arg, i.e. less flexible but simpler, and easier to identify without making mistakes.