Overwrite default configuration

[isvoboda]

My use-case includes predefined configuration of an experiment based on the suggestion from #386 (comment)

I do not know how to redefine the selection of group model in defaults:

• conf/config.yaml

defaults:
  model: UNetPix

• conf/model/UNetPix.yaml

model:
  class: models.UNet.UNetPix
    params:
      kwarg1: ...
      kwarg2: ...

• conf/model/UNetTC.yaml

model:
  class: models.UNet.UNetTC
    params:
      kwarg1: ...
      kwarg2: ...

I would like to add configuration of an experiment where the UNetTC node replaces the UNetPix.

• conf/experiment/UNetTC.yaml

model: UNetTC # Here I would like to replace UNetPix by UNetTC defined in model/UNetTC.yaml
... # other experiment related configurations

I can set the model as model: UNetTC which resolves to string UNetTC but the desired outcome should be the whole node defined in models/UNetTC.yaml.

Is this currently possible?

[omry]

The only supported way to override the defaults list when using @hydra.main() is through the command line.

python foo.py model=UNetTC

I suspect what you really want would be addressed by the potential support for recursive defaults. but this is not something that will happen soon and I still have some questions about it's viability.

See #171 for the info about the task to add recursive detaults.

[omry]

An alternative workaround would come once support for an alternative primary config is introduced.
that way you will be able to have a defaults list in your alternative primary config. this is likely be supported before recursive defaults.