Added function to load the state_dict from the diffusion model into t… (#478)

* Added function to load the state_dict from the diffusion model into the controlnet, informing the user - if required - of matched and unmatched layers.

* Modify formatting: removed return statement, return in args description, and formatted the print with f-Strings.

* Formatting of the function

---------

Co-authored-by: virginiafdez <[email protected]>

Author: virginiafdez

generative/networks/nets/controlnet.py

@@ -41,7 +41,6 @@
 
 from generative.networks.nets.diffusion_model_unet import get_down_block, get_mid_block, get_timestep_embedding
 
-
 class ControlNetConditioningEmbedding(nn.Module):
     """
     Network to encode the conditioning into a latent space.
@@ -121,6 +120,26 @@ def zero_module(module):
         nn.init.zeros_(p)
     return module
 
+def copy_weights_to_controlnet(controlnet : nn.Module,
+                               diffusion_model: nn.Module,
+                               verbose: bool = True) -> None:
+    '''
+    Copy the state dict from the input diffusion model to the ControlNet, printing, if user requires it, the output
+    keys that have matched and those that haven't.
+
+    Args:
+        controlnet: instance of ControlNet
+        diffusion_model: instance of DiffusionModelUnet or SPADEDiffusionModelUnet
+        verbose: if True, the matched and unmatched keys will be printed.
+    '''
+
+    output = controlnet.load_state_dict(diffusion_model.state_dict(), strict = False)
+    if verbose:
+        dm_keys = [p[0] for p in list(diffusion_model.named_parameters()) if p[0] not in output.unexpected_keys]
+        print(f"Copied weights from {len(dm_keys)} keys of the diffusion model into the ControlNet:"
+              f"\n{'; '.join(dm_keys)}\nControlNet missing keys: {len(output.missing_keys)}:"
+              f"\n{'; '.join(output.missing_keys)}\nDiffusion model incompatible keys: {len(output.unexpected_keys)}:"
+              f"\n{'; '.join(output.unexpected_keys)}")
 
 class ControlNet(nn.Module):
     """