[Feature] 28 Make models switchable through the config (#45)

* feat: make model instantiateable

* docs: instantiation explained in changelog

* refactor: rename model config object

* fix: rename config to model_config

* fix: mark non-recursive

* docs: changelog

CHANGELOG.md

@@ -35,6 +35,7 @@ Keep it human-readable, your future self will thank you!
 - Update CI to inherit from common infrastructue reusable workflows
 - run downstream-ci only when src and tests folders have changed
 - New error messages for wrongs graphs.
+- Feature: Change model to be instantiatable in the interface, addressing [#28](https://github.com/ecmwf/anemoi-models/issues/28) through [#45](https://github.com/ecmwf/anemoi-models/pulls/45)
 
 ### Removed
 

src/anemoi/models/interface/__init__.py

@@ -14,7 +14,6 @@
 from hydra.utils import instantiate
 from torch_geometric.data import HeteroData
 
-from anemoi.models.models.encoder_processor_decoder import AnemoiModelEncProcDec
 from anemoi.models.preprocessing import Processors
 
 
@@ -73,9 +72,13 @@ def _build_model(self) -> None:
         self.pre_processors = Processors(processors)
         self.post_processors = Processors(processors, inverse=True)
 
-        # Instantiate the model (Can be generalised to other models in the future, here we use AnemoiModelEncProcDec)
-        self.model = AnemoiModelEncProcDec(
-            config=self.config, data_indices=self.data_indices, graph_data=self.graph_data
+        # Instantiate the model
+        self.model = instantiate(
+            self.config.model.model,
+            model_config=self.config,
+            data_indices=self.data_indices,
+            graph_data=self.graph_data,
+            _recursive_=False,  # Disables recursive instantiation by Hydra
         )
 
         # Use the forward method of the model directly

src/anemoi/models/models/encoder_processor_decoder.py

@@ -32,16 +32,16 @@ class AnemoiModelEncProcDec(nn.Module):
     def __init__(
         self,
         *,
-        config: DotDict,
+        model_config: DotDict,
         data_indices: dict,
         graph_data: HeteroData,
     ) -> None:
         """Initializes the graph neural network.
 
         Parameters
         ----------
-        config : DotDict
-            Job configuration
+        model_config : DotDict
+            Model configuration
         data_indices : dict
             Data indices
         graph_data : HeteroData
@@ -50,15 +50,15 @@ def __init__(
         super().__init__()
 
         self._graph_data = graph_data
-        self._graph_name_data = config.graph.data
-        self._graph_name_hidden = config.graph.hidden
+        self._graph_name_data = model_config.graph.data
+        self._graph_name_hidden = model_config.graph.hidden
 
         self._calculate_shapes_and_indices(data_indices)
         self._assert_matching_indices(data_indices)
 
-        self.multi_step = config.training.multistep_input
+        self.multi_step = model_config.training.multistep_input
 
-        self._define_tensor_sizes(config)
+        self._define_tensor_sizes(model_config)
 
         # Create trainable tensors
         self._create_trainable_attributes()
@@ -69,13 +69,13 @@ def __init__(
 
         self.data_indices = data_indices
 
-        self.num_channels = config.model.num_channels
+        self.num_channels = model_config.model.num_channels
 
         input_dim = self.multi_step * self.num_input_channels + self.latlons_data.shape[1] + self.trainable_data_size
 
         # Encoder data -> hidden
         self.encoder = instantiate(
-            config.model.encoder,
+            model_config.model.encoder,
             in_channels_src=input_dim,
             in_channels_dst=self.latlons_hidden.shape[1] + self.trainable_hidden_size,
             hidden_dim=self.num_channels,
@@ -86,7 +86,7 @@ def __init__(
 
         # Processor hidden -> hidden
         self.processor = instantiate(
-            config.model.processor,
+            model_config.model.processor,
             num_channels=self.num_channels,
             sub_graph=self._graph_data[(self._graph_name_hidden, "to", self._graph_name_hidden)],
             src_grid_size=self._hidden_grid_size,
@@ -95,7 +95,7 @@ def __init__(
 
         # Decoder hidden -> data
         self.decoder = instantiate(
-            config.model.decoder,
+            model_config.model.decoder,
             in_channels_src=self.num_channels,
             in_channels_dst=input_dim,
             hidden_dim=self.num_channels,
@@ -109,7 +109,7 @@ def __init__(
         self.boundings = nn.ModuleList(
             [
                 instantiate(cfg, name_to_index=self.data_indices.model.output.name_to_index)
-                for cfg in getattr(config.model, "bounding", [])
+                for cfg in getattr(model_config.model, "bounding", [])
             ]
         )