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import numpy as np
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from torch.nn import MultiheadAttention, TransformerEncoder, TransformerEncoderLayer
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from scipy.stats import pearsonr, spearmanr
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from utils import mse_loss, torch_corr_x_y
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class ConstructAdjMatrix(nn.Module):
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"""Constructs adjacency matrices for graph-based operations."""
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def __init__(self, original_adj_mat, device="cpu"):
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super().__init__()
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# Convert numpy array to torch tensor if needed
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self.adj = torch.from_numpy(original_adj_mat).float() if isinstance(original_adj_mat, np.ndarray) else original_adj_mat
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self.adj = self.adj.to(device)
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self.device = device
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def forward(self):
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"""Computes Laplacian matrices for cells and drugs."""
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with torch.no_grad():
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# Compute degree matrices for normalization
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d_x = torch.diag(torch.pow(torch.sum(self.adj, dim=1) + 1, -0.5))
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d_y = torch.diag(torch.pow(torch.sum(self.adj, dim=0) + 1, -0.5))
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# Compute aggregated Laplacian matrices
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agg_cell_lp = torch.mm(torch.mm(d_x, self.adj), d_y)
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agg_drug_lp = torch.mm(torch.mm(d_y, self.adj.T), d_x)
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# Compute self-loop Laplacian matrices
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self_cell_lp = torch.diag(torch.add(torch.pow(torch.sum(self.adj, dim=1) + 1, -1), 1))
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self_drug_lp = torch.diag(torch.add(torch.pow(torch.sum(self.adj, dim=0) + 1, -1), 1))
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return agg_cell_lp.to(self.device), agg_drug_lp.to(self.device), self_cell_lp.to(self.device), self_drug_lp.to(self.device)
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class LoadFeature(nn.Module):
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"""Loads and processes cell and drug features."""
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def __init__(self, cell_exprs, drug_fingerprints, device="cpu"):
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super().__init__()
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self.device = device
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# Convert input data to torch tensors
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self.cell_exprs = torch.from_numpy(cell_exprs).float().to(device)
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self.drug_fingerprints = [torch.from_numpy(fp).float().to(device) for fp in drug_fingerprints]
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# Define projection layers for drug fingerprints
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self.drug_proj = nn.ModuleList([
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nn.Sequential(
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nn.Linear(fp.shape[1], 512),
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nn.BatchNorm1d(512),
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nn.GELU(),
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nn.Dropout(0.3)
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).to(device) for fp in drug_fingerprints
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])
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# Initialize transformer encoder for drug features
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self.transformer = TransformerEncoder(
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TransformerEncoderLayer(d_model=512, nhead=8, dim_feedforward=2048, batch_first=True),
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num_layers=3
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).to(device)
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# Normalization layers
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self.cell_norm = nn.LayerNorm(cell_exprs.shape[1]).to(device)
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self.drug_norm = nn.LayerNorm(512).to(device)
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# Cell feature encoder
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self.cell_encoder = nn.Sequential(
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nn.Linear(cell_exprs.shape[1], 1024),
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nn.BatchNorm1d(1024),
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nn.GELU(),
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nn.Dropout(0.3),
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nn.Linear(1024, 512)
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).to(device)
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def forward(self):
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"""Processes cell and drug features to generate encoded representations."""
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# Normalize and encode cell features
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cell_feat = self.cell_norm(self.cell_exprs)
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cell_encoded = self.cell_encoder(cell_feat)
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# Project and process drug fingerprints
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projected = [proj(fp) for proj, fp in zip(self.drug_proj, self.drug_fingerprints)]
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stacked = torch.stack(projected, dim=1)
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drug_feat = self.transformer(stacked)
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drug_feat = self.drug_norm(drug_feat.mean(dim=1))
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return cell_encoded, drug_feat
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class GEncoder(nn.Module):
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"""Encodes cell and drug features using graph-based operations."""
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def __init__(self, agg_c_lp, agg_d_lp, self_c_lp, self_d_lp, device="cpu"):
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super().__init__()
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self.agg_c_lp = agg_c_lp
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self.agg_d_lp = agg_d_lp
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self.self_c_lp = self_c_lp
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self.self_d_lp = self_d_lp
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self.device = device
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# Cell feature encoder
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self.cell_encoder = nn.Sequential(
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nn.Linear(512, 1024),
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nn.BatchNorm1d(1024),
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nn.GELU(),
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nn.Dropout(0.3),
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nn.Linear(1024, 512)
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).to(device)
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# Drug feature encoder
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self.drug_encoder = nn.Sequential(
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nn.Linear(512, 1024),
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nn.BatchNorm1d(1024),
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nn.GELU(),
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nn.Dropout(0.3),
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nn.Linear(1024, 512)
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).to(device)
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# Attention mechanism and residual connection
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self.attention = MultiheadAttention(embed_dim=512, num_heads=8, batch_first=True).to(device)
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self.residual = nn.Linear(512, 512).to(device)
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self.fc = nn.Sequential(
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nn.Linear(1024, 512),
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nn.BatchNorm1d(512),
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nn.GELU(),
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nn.Dropout(0.2)
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).to(device)
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def forward(self, cell_f, drug_f):
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"""Encodes cell and drug features with graph-based attention."""
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# Aggregate features using Laplacian matrices
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cell_agg = torch.mm(self.agg_c_lp, drug_f) + torch.mm(self.self_c_lp, cell_f)
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drug_agg = torch.mm(self.agg_d_lp, cell_f) + torch.mm(self.self_d_lp, drug_f)
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# Encode aggregated features
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cell_fc = self.cell_encoder(cell_agg)
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drug_fc = self.drug_encoder(drug_agg)
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# Apply attention mechanism
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attn_output, _ = self.attention(
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query=cell_fc.unsqueeze(0),
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key=drug_fc.unsqueeze(0),
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value=drug_fc.unsqueeze(0)
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)
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attn_output = attn_output.squeeze(0)
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cell_emb = cell_fc + self.residual(attn_output)
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# Apply final activation
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cell_emb = F.gelu(cell_emb)
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drug_emb = F.gelu(drug_fc)
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return cell_emb, drug_emb
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class GDecoder(nn.Module):
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"""Decodes combined cell and drug embeddings to predict scores."""
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def __init__(self, emb_dim, gamma):
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super().__init__()
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self.gamma = gamma
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# Decoder network
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self.decoder = nn.Sequential(
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nn.Linear(2 * emb_dim, 1024),
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nn.BatchNorm1d(1024),
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nn.GELU(),
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nn.Dropout(0.2),
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nn.Linear(1024, 1)
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)
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# Learnable correlation weight
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self.corr_weight = nn.Parameter(torch.tensor(0.5))
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def forward(self, cell_emb, drug_emb):
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"""Generates prediction scores from cell and drug embeddings."""
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# Combine cell and drug embeddings
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cell_exp = cell_emb.unsqueeze(1).repeat(1, drug_emb.size(0), 1)
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drug_exp = drug_emb.unsqueeze(0).repeat(cell_emb.size(0), 1, 1)
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combined = torch.cat([cell_exp, drug_exp], dim=-1)
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# Decode combined features
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scores = self.decoder(combined.view(-1, 2 * cell_emb.size(1))).view(cell_emb.size(0), drug_emb.size(0))
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corr = torch_corr_x_y(cell_emb, drug_emb)
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# Combine scores and correlation
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return self.gamma * (self.corr_weight * scores + (1 - self.corr_weight) * corr)
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class DeepTraCDR(nn.Module):
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"""Graph Convolutional Network for cell-drug interaction prediction."""
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def __init__(self, adj_mat, cell_exprs, drug_finger, layer_size, gamma, device="cpu"):
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super().__init__()
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self.device = device
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# Convert adjacency matrix to tensor if needed
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self.adj_mat = torch.from_numpy(adj_mat).float().to(device) if isinstance(adj_mat, np.ndarray) else adj_mat.to(device)
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# Initialize components
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self.construct_adj = ConstructAdjMatrix(self.adj_mat, device=device)
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self.load_feat = LoadFeature(cell_exprs, drug_finger, device=device)
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# Precompute adjacency matrices
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agg_c, agg_d, self_c, self_d = self.construct_adj()
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# Initialize encoder and decoder
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self.encoder = GEncoder(agg_c, agg_d, self_c, self_d, device=device).to(device)
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self.decoder = GDecoder(layer_size[-1], gamma).to(device)
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def forward(self):
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"""Generates predictions and embeddings for cell-drug interactions."""
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cell_f, drug_f = self.load_feat()
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cell_emb, drug_emb = self.encoder(cell_f, drug_f)
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return self.decoder(cell_emb, drug_emb), cell_emb, drug_emb
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class Optimizer:
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"""Handles training and evaluation of the DeepTraCDR model."""
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def __init__(self, model, train_data, test_data, test_mask, train_mask, adj_matrix,
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lr=0.001, wd=1e-05, epochs=200, test_freq=20, device="cpu", patience=50):
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self.model = model.to(device)
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self.train_data = train_data.float().to(device)
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self.test_data = test_data.float().to(device)
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self.train_mask = train_mask.to(device)
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self.test_mask = test_mask.to(device).bool()
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self.adj_matrix = adj_matrix.to(device)
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self.optimizer = torch.optim.Adam(self.model.parameters(), lr=lr, weight_decay=wd)
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self.epochs = epochs
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self.test_freq = test_freq
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self.patience = patience
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self.best_rmse = float('inf')
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self.epochs_no_improve = 0
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self.true_masked_np = torch.masked_select(self.test_data, self.test_mask).cpu().numpy()
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def evaluate_metrics(self, pred_tensor):
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"""Computes RMSE, PCC, and SCC for model evaluation."""
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pred_masked_np = torch.masked_select(pred_tensor, self.test_mask).cpu().numpy()
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rmse = np.sqrt(np.mean((self.true_masked_np - pred_masked_np)**2))
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pcc, _ = pearsonr(self.true_masked_np, pred_masked_np)
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scc, _ = spearmanr(self.true_masked_np, pred_masked_np)
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return rmse, pcc, scc, pred_masked_np
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def train(self):
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"""Trains the model with early stopping based on RMSE."""
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best_rmse = float('inf')
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best_pcc = 0.0
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best_scc = 0.0
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best_pred_np = None
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for epoch in range(self.epochs):
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self.model.train()
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pred, cell_emb, drug_emb = self.model()
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# Compute and optimize loss
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mse_loss_val = mse_loss(self.train_data, pred, self.train_mask)
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total_loss = mse_loss_val
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self.optimizer.zero_grad()
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total_loss.backward()
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self.optimizer.step()
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if epoch % self.test_freq == 0:
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self.model.eval()
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with torch.no_grad():
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pred_eval, _, _ = self.model()
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rmse, pcc, scc, pred_masked = self.evaluate_metrics(pred_eval)
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# Update early stopping criteria
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if rmse < self.best_rmse:
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self.best_rmse = rmse
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self.epochs_no_improve = 0
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else:
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self.epochs_no_improve += 1
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# Track best results
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if rmse < best_rmse:
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best_rmse = rmse
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best_pcc = pcc
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best_scc = scc
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best_pred_np = pred_masked.copy()
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print(f"Epoch {epoch}: Loss = {total_loss.item():.4f}, RMSE = {rmse:.4f}, PCC = {pcc:.4f}, SCC = {scc:.4f}")
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# Early stopping
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if self.epochs_no_improve >= self.patience:
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print(f"Early stopping at epoch {epoch} (no improvement for {self.patience} epochs).")
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break
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print("\nBest Results:")
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print(f"RMSE: {best_rmse:.4f}")
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print(f"PCC: {best_pcc:.4f}")
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print(f"SCC: {best_scc:.4f}")
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return self.true_masked_np, best_pred_np, best_rmse, best_pcc, best_scc |