resolved

unlearning/WeightFiltration.py

@@ -50,7 +50,6 @@ class WeightFiltration(Strategy):
         for epoch in range(self.epochs):
             t_loss_r, t_loss_f = 0.0, 0.0
             steps = 0
-
             # forget and retain
             for (r_inputs, r_labels), (f_inputs, f_labels) in zip(retain_loader, forget_loader):
                 r_inputs, r_labels = r_inputs.to(device), r_labels.to(device)

unlearning/wf/WF_Net.py

@@ -0,0 +1,86 @@
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+class WF_Net(nn.Module):
+    """
+    Implements Poppi et al.'s WF Model structure.
+    Wraps a pre-trained ResNet-18 and dynamically applies 
+    weight-space gating matrix multiplication during the forward step.
+    """
+    def __init__(self, original_model: nn.Module, num_classes: int):
+        super().__init__()
+        # Extract the sequence of blocks/layers L from the original model
+        self.conv1 = original_model.conv1
+        self.bn1 = original_model.bn1
+        self.relu = original_model.relu
+        self.maxpool = original_model.maxpool
+        
+        self.layer1 = original_model.layer1
+        self.layer2 = original_model.layer2
+        self.layer3 = original_model.layer3
+        self.layer4 = original_model.layer4
+        
+        self.avgpool = original_model.avgpool
+        self.fc = original_model.fc
+        
+        # Target layer for filtering: layer4 block 1 conv2
+        # We extract its static tensor data out of the autograd parameter pool
+        self.target_conv = self.layer4[1].conv2
+        self.original_w = nn.Parameter(self.target_conv.weight.data.clone().detach(), requires_grad=False)
+        
+        # Require: Alpha gating matrix. Shape: (num_classes, out_channels)
+        # Initialized to 1.5 as per Poppi et al.'s verbatim specification
+        out_channels = self.original_w.shape[0]
+        #self.alpha = nn.Parameter(torch.ones(num_classes, out_channels) * 1.5)
+        self.alpha = nn.Parameter(torch.ones(num_classes, out_channels))
+
+    def forward(self, x: torch.Tensor, target_class_indices: torch.Tensor) -> torch.Tensor:
+        # 1. Run through early sequence of layers undisturbed
+        x = self.maxpool(self.relu(self.bn1(self.conv1(x))))
+        x = self.layer1(x)
+        x = self.layer2(x)
+        x = self.layer3(x)
+                
+        # Run layer4 block 0 normally
+        x = self.layer4[0](x)
+        
+        # -------------------------------------------------------------
+        # HERE IT IS: Save the structural skip connection (identity) 
+        # BEFORE modifying features via block 1's convolutions
+        # -------------------------------------------------------------
+        identity = x 
+                
+        # Now enter layer4 block 1
+        x = self.layer4[1].conv1(x)
+        x = self.layer4[1].bn1(x)
+        x = self.layer4[1].relu(x)
+                
+        # [Your Step 1 Masking Math happens right here...]
+        batch_alpha = self.alpha[target_class_indices]
+        mask = torch.sigmoid(batch_alpha).view(x.size(0), -1, 1, 1)
+        
+        # Run the functional convolution
+        x = F.conv2d(
+            x, 
+            weight=self.original_w, 
+            bias=self.target_conv.bias, 
+            stride=self.target_conv.stride, 
+            padding=self.target_conv.padding
+        )
+        
+        # Apply your WF-Net channel mask
+        x = x * mask 
+        x = self.layer4[1].bn2(x)
+                
+        # -------------------------------------------------------------
+        # HERE IT IS USED: Add the pristine identity back to the gated output
+        # -------------------------------------------------------------
+        x = self.layer4[1].relu(x + identity) 
+                
+        # Final Classification Head Sequence
+        x = self.avgpool(x)
+        x = torch.flatten(x, 1)
+        y_out = self.fc(x)
+                
+        return y_out