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hypertower/classes/v2/models.py
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2026-03-02 06:44:22 +01:00

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Python

"""V2 model classes and training/inference helpers."""
from __future__ import annotations
from random import random
from typing import Optional
import numpy as np
import torch
import torch.nn.functional as F
from torch import nn
from torch.utils.data import DataLoader
from classes.v2.bridges import Bridge
from classes.v2.towers import ImageTower, MDTower
# ---------------------------------------------------------------------------
# Model classes
# ---------------------------------------------------------------------------
class SingleEyeHT(nn.Module):
"""
ImageTower + MDTower + Bridge, trained on eye-level samples.
Supports both Classic (eye-level) and Ensemble (patient-level averaging) eval.
"""
def __init__(
self,
*,
backbone: str,
freeze_ratio: float,
augment: bool,
clinical_data,
num_classes: int,
md_hidden_dim: int = 128,
fusion_dim: int = 256,
):
super().__init__()
self.img_tower = ImageTower(
backbone=backbone,
freeze_ratio=freeze_ratio,
augment=augment,
use_se=False,
)
self.md_tower = MDTower(
clinical_data=clinical_data,
hidden_dim=md_hidden_dim,
use_se=False,
)
self.bridge = Bridge(
img_dim=self.img_tower.out_dim,
meta_dim=self.md_tower.out_dim,
num_classes=num_classes,
fusion_dim=fusion_dim,
mode="fused",
use_se=False,
)
@property
def transform(self):
return self.img_tower.transform
def forward(self, x: torch.Tensor, meta: torch.Tensor) -> torch.Tensor:
img_feats = self.img_tower(x)
md_feats = self.md_tower(meta)
out_f, _, _ = self.bridge(img_feats, md_feats)
return out_f
class BilateralHT(nn.Module):
"""
Bilateral mode with joint towers:
- shared eye-level towers encode OD/OS independently
- joint image and metadata towers combine OD/OS embeddings
- standard Bridge fuses joint image + joint metadata embeddings
"""
def __init__(
self,
*,
backbone: str,
freeze_ratio: float,
augment: bool,
clinical_data,
num_classes: int,
md_hidden_dim: int = 128,
fusion_dim: int = 256,
):
super().__init__()
self.eye_img_tower = ImageTower(
backbone=backbone,
freeze_ratio=freeze_ratio,
augment=augment,
use_se=False,
)
self.eye_md_tower = MDTower(
clinical_data=clinical_data,
hidden_dim=md_hidden_dim,
use_se=False,
)
img_dim = self.eye_img_tower.out_dim
md_dim = self.eye_md_tower.out_dim
self.joint_img = nn.Sequential(
nn.Linear(2 * img_dim, fusion_dim),
nn.LayerNorm(fusion_dim),
nn.ReLU(),
nn.Dropout(0.3),
nn.Linear(fusion_dim, img_dim),
)
self.joint_md = nn.Sequential(
nn.Linear(2 * md_dim, fusion_dim),
nn.LayerNorm(fusion_dim),
nn.ReLU(),
nn.Dropout(0.3),
nn.Linear(fusion_dim, md_dim),
)
self.bridge = Bridge(
img_dim=img_dim,
meta_dim=md_dim,
num_classes=num_classes,
fusion_dim=fusion_dim,
mode="fused",
use_se=False,
)
# Auxiliary heads for tower warmup / BCD tower steps.
self.aux_img = nn.Linear(img_dim, num_classes)
self.aux_md = nn.Linear(md_dim, num_classes)
@property
def transform(self):
return self.eye_img_tower.transform
def encode_joint(
self,
x_od: torch.Tensor,
meta_od: torch.Tensor,
x_os: torch.Tensor,
meta_os: torch.Tensor,
) -> tuple[torch.Tensor, torch.Tensor]:
img_od = self.eye_img_tower(x_od)
md_od = self.eye_md_tower(meta_od)
img_os = self.eye_img_tower(x_os)
md_os = self.eye_md_tower(meta_os)
joint_img = self.joint_img(torch.cat([img_od, img_os], dim=1))
joint_md = self.joint_md(torch.cat([md_od, md_os], dim=1))
return joint_img, joint_md
def forward(
self,
x_od: torch.Tensor,
meta_od: torch.Tensor,
x_os: torch.Tensor,
meta_os: torch.Tensor,
) -> torch.Tensor:
joint_img, joint_md = self.encode_joint(x_od, meta_od, x_os, meta_os)
out_f, _, _ = self.bridge(joint_img, joint_md)
return out_f
class FusedEnsembleHT(nn.Module):
"""
SingleEyeHT base with a per-eye attention scorer for bilateral fusion.
The base model is trained eye-level (identical to ensemble mode).
After base training completes, the base is frozen and only the
eye_scorer is trained on bilateral (patient-level) samples.
At inference, eye_scorer is applied independently to each eye's logit
vector to produce a scalar attention score. Softmax over the two scores
gives attention weights; the final logit is a weighted sum:
score_od = eye_scorer(logit_od) # [B, 1]
score_os = eye_scorer(logit_os) # [B, 1]
alpha = softmax([score_od, score_os]) # [B, 2], sums to 1
out = alpha[:,0:1]*logit_od + alpha[:,1:2]*logit_os
Because eye_scorer is applied to each eye with the same weights, the
mechanism is permutation-equivariant — there is no left/right positional
bias. Through training on bilateral labels the scorer learns to give high
scores to logits that point strongly toward the GC class, creating the
desired asymmetry: a confidently GC eye dominates the patient prediction
more than a comparably confident healthy eye would.
"""
def __init__(self, base: SingleEyeHT, num_classes: int):
super().__init__()
self.base = base
# Applied independently to each eye's logit → scalar attention score.
# Learns the GC-direction in logit space from bilateral labels.
self.eye_scorer = nn.Linear(num_classes, 1, bias=True)
def forward(
self,
x_od: torch.Tensor,
meta_od: torch.Tensor,
x_os: torch.Tensor,
meta_os: torch.Tensor,
) -> torch.Tensor:
logit_od = self.base(x_od, meta_od) # [B, C]
logit_os = self.base(x_os, meta_os) # [B, C]
scores = torch.cat([self.eye_scorer(logit_od),
self.eye_scorer(logit_os)], dim=1) # [B, 2]
alpha = torch.softmax(scores, dim=1) # [B, 2]
return alpha[:, 0:1] * logit_od + alpha[:, 1:2] * logit_os # [B, C]
# ---------------------------------------------------------------------------
# Phase control
# ---------------------------------------------------------------------------
def _set_requires_grad(module: nn.Module, enabled: bool) -> None:
for p in module.parameters():
p.requires_grad = enabled
def _set_single_phase(model: SingleEyeHT, phase: str) -> None:
if phase == "tower_warmup":
_set_requires_grad(model.img_tower, True)
_set_requires_grad(model.md_tower, True)
_set_requires_grad(model.bridge.classifier_img, True)
_set_requires_grad(model.bridge.classifier_md, True)
_set_requires_grad(model.bridge.W_img, False)
_set_requires_grad(model.bridge.W_md, False)
_set_requires_grad(model.bridge.classifier_fused, False)
return
if phase == "fused_warmup":
_set_requires_grad(model.img_tower, False)
_set_requires_grad(model.md_tower, False)
_set_requires_grad(model.bridge.classifier_img, False)
_set_requires_grad(model.bridge.classifier_md, False)
_set_requires_grad(model.bridge.W_img, True)
_set_requires_grad(model.bridge.W_md, True)
_set_requires_grad(model.bridge.classifier_fused, True)
return
_set_requires_grad(model, True)
def _set_bilateral_phase(model: BilateralHT, phase: str) -> None:
if phase == "tower_warmup":
_set_requires_grad(model.eye_img_tower, True)
_set_requires_grad(model.eye_md_tower, True)
_set_requires_grad(model.joint_img, True)
_set_requires_grad(model.joint_md, True)
_set_requires_grad(model.aux_img, True)
_set_requires_grad(model.aux_md, True)
_set_requires_grad(model.bridge, False)
return
if phase == "fused_warmup":
_set_requires_grad(model.eye_img_tower, False)
_set_requires_grad(model.eye_md_tower, False)
_set_requires_grad(model.joint_img, False)
_set_requires_grad(model.joint_md, False)
_set_requires_grad(model.aux_img, False)
_set_requires_grad(model.aux_md, False)
_set_requires_grad(model.bridge, True)
return
_set_requires_grad(model, True)
# ---------------------------------------------------------------------------
# Training helpers
# ---------------------------------------------------------------------------
def train_single_epoch(
model: SingleEyeHT,
loader: DataLoader,
opt,
device: torch.device,
*,
phase: str,
bcd_prob: float = 0.5,
) -> tuple[float, float]:
model.train()
_set_single_phase(model, phase)
total_loss = total_correct = total_n = 0
for batch in loader:
x = batch.get("image_1")
m = batch.get("matrix_1")
y = batch.get("label_1")
if not torch.is_tensor(x) or not torch.is_tensor(m):
continue
x = x.to(device)
m = m.to(device)
y = _to_label_tensor(y, device)
img_feats = model.img_tower(x)
md_feats = model.md_tower(m)
if phase == "tower_warmup":
logits_i = model.bridge.classifier_img(img_feats)
logits_m = model.bridge.classifier_md(md_feats)
loss = 0.5 * (F.cross_entropy(logits_i, y) + F.cross_entropy(logits_m, y))
logits = 0.5 * (F.softmax(logits_i, dim=1) + F.softmax(logits_m, dim=1))
elif phase == "fused_warmup":
logits, _, _ = model.bridge(img_feats, md_feats)
loss = F.cross_entropy(logits, y)
else:
if random() < bcd_prob:
if random() < 0.5:
logits = model.bridge.classifier_img(img_feats)
else:
logits = model.bridge.classifier_md(md_feats)
loss = F.cross_entropy(logits, y)
else:
logits, _, _ = model.bridge(img_feats, md_feats)
loss = F.cross_entropy(logits, y)
opt.zero_grad()
loss.backward()
opt.step()
bs = y.shape[0]
total_loss += float(loss.item()) * bs
total_correct += int((logits.argmax(1) == y).sum())
total_n += bs
return (
total_loss / total_n if total_n else float("nan"),
total_correct / total_n if total_n else float("nan"),
)
def train_bilateral_epoch(
model: BilateralHT,
loader: DataLoader,
opt,
device: torch.device,
*,
phase: str,
bcd_prob: float = 0.5,
) -> tuple[float, float]:
model.train()
_set_bilateral_phase(model, phase)
total_loss = total_correct = total_n = 0
for batch in loader:
x1 = batch.get("image_1")
m1 = batch.get("matrix_1")
x2 = batch.get("image_2")
m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
x1 = x1.to(device); m1 = m1.to(device)
x2 = x2.to(device); m2 = m2.to(device)
y = _to_label_tensor(y, device)
joint_img, joint_md = model.encode_joint(x1, m1, x2, m2)
if phase == "tower_warmup":
logits_i = model.aux_img(joint_img)
logits_m = model.aux_md(joint_md)
loss = 0.5 * (F.cross_entropy(logits_i, y) + F.cross_entropy(logits_m, y))
logits = 0.5 * (F.softmax(logits_i, dim=1) + F.softmax(logits_m, dim=1))
elif phase == "fused_warmup":
logits, _, _ = model.bridge(joint_img, joint_md)
loss = F.cross_entropy(logits, y)
else:
if random() < bcd_prob:
if random() < 0.5:
logits = model.aux_img(joint_img)
else:
logits = model.aux_md(joint_md)
loss = F.cross_entropy(logits, y)
else:
logits, _, _ = model.bridge(joint_img, joint_md)
loss = F.cross_entropy(logits, y)
opt.zero_grad()
loss.backward()
opt.step()
bs = y.shape[0]
total_loss += float(loss.item()) * bs
total_correct += int((logits.argmax(1) == y).sum())
total_n += bs
return (
total_loss / total_n if total_n else float("nan"),
total_correct / total_n if total_n else float("nan"),
)
def train_fusion_epoch(
model: FusedEnsembleHT,
loader: DataLoader,
opt,
device: torch.device,
) -> tuple[float, float]:
"""Train only the fusion head; the base SingleEyeHT is frozen in eval mode."""
model.base.eval()
model.eye_scorer.train()
total_loss = total_correct = total_n = 0
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and
torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
out = model(x1.to(device), m1.to(device), x2.to(device), m2.to(device))
loss = F.cross_entropy(out, y_t)
opt.zero_grad()
loss.backward()
opt.step()
bs = y_t.shape[0]
total_loss += float(loss.item()) * bs
total_correct += int((out.argmax(1) == y_t).sum())
total_n += bs
return (
total_loss / total_n if total_n else float("nan"),
total_correct / total_n if total_n else float("nan"),
)
# ---------------------------------------------------------------------------
# Inference helpers
# ---------------------------------------------------------------------------
def _to_label_tensor(labels, device: torch.device) -> torch.Tensor:
if torch.is_tensor(labels):
return labels.to(device=device, dtype=torch.long)
return torch.as_tensor(labels, dtype=torch.long, device=device)
def collect_probs_classic(
model: SingleEyeHT,
loader: DataLoader,
device: torch.device,
) -> tuple[np.ndarray, np.ndarray]:
"""
Classic eye-level eval using the bilateral val loader.
OD and OS are treated as independent samples (both contribute to the
arrays with the same patient label). Returns (y_true [2N], probs [2N, C]).
"""
model.eval()
y_chunks, p_chunks = [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
p_od = F.softmax(model(x1.to(device), m1.to(device)), dim=1)
p_os = F.softmax(model(x2.to(device), m2.to(device)), dim=1)
y_np = y_t.cpu().numpy()
y_chunks += [y_np, y_np]
p_chunks += [p_od.cpu().numpy(), p_os.cpu().numpy()]
if not y_chunks:
return np.array([], dtype=np.int64), np.zeros((0, 0), dtype=np.float32)
return np.concatenate(y_chunks), np.concatenate(p_chunks, axis=0)
def collect_probs_ensemble(
model: SingleEyeHT,
loader: DataLoader,
device: torch.device,
) -> tuple[np.ndarray, np.ndarray]:
"""
Patient-level ensemble eval: average OD and OS softmax probabilities.
Returns (y_true [N], probs [N, C]).
"""
model.eval()
y_chunks, p_chunks = [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
p_od = F.softmax(model(x1.to(device), m1.to(device)), dim=1)
p_os = F.softmax(model(x2.to(device), m2.to(device)), dim=1)
p = 0.5 * (p_od + p_os)
y_chunks.append(y_t.cpu().numpy())
p_chunks.append(p.cpu().numpy())
if not y_chunks:
return np.array([], dtype=np.int64), np.zeros((0, 0), dtype=np.float32)
return np.concatenate(y_chunks), np.concatenate(p_chunks, axis=0)
def collect_probs_bilateral(
model: BilateralHT,
loader: DataLoader,
device: torch.device,
) -> tuple[np.ndarray, np.ndarray]:
"""Patient-level bilateral eval. Returns (y_true [N], probs [N, C])."""
model.eval()
y_chunks, p_chunks = [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
p = F.softmax(model(x1.to(device), m1.to(device), x2.to(device), m2.to(device)), dim=1)
y_chunks.append(y_t.cpu().numpy())
p_chunks.append(p.cpu().numpy())
if not y_chunks:
return np.array([], dtype=np.int64), np.zeros((0, 0), dtype=np.float32)
return np.concatenate(y_chunks), np.concatenate(p_chunks, axis=0)
def collect_probs_fused(
model: FusedEnsembleHT,
loader: DataLoader,
device: torch.device,
) -> tuple[np.ndarray, np.ndarray]:
"""Patient-level fused-head eval. Returns (y_true [N], probs [N, C])."""
model.eval()
y_chunks, p_chunks = [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and
torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
p = F.softmax(model(x1.to(device), m1.to(device),
x2.to(device), m2.to(device)), dim=1)
y_chunks.append(y_t.cpu().numpy())
p_chunks.append(p.cpu().numpy())
if not y_chunks:
return np.array([], dtype=np.int64), np.zeros((0, 0), dtype=np.float32)
return np.concatenate(y_chunks), np.concatenate(p_chunks, axis=0)
def collect_probs_single_components(
model: SingleEyeHT,
loader: DataLoader,
device: torch.device,
*,
aggregate_patient: bool,
) -> tuple[np.ndarray, np.ndarray, np.ndarray, np.ndarray]:
"""
Collect fused/img/md probabilities for SingleEyeHT.
- aggregate_patient=False: eye-level (OD/OS as independent samples)
- aggregate_patient=True : patient-level (average OD/OS per head)
"""
model.eval()
y_chunks = []
pf_chunks, pi_chunks, pm_chunks = [], [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
def _per_eye_probs(x, m):
img_feats = model.img_tower(x.to(device))
md_feats = model.md_tower(m.to(device))
out_f, out_i, out_m = model.bridge(img_feats, md_feats)
return (
F.softmax(out_f, dim=1),
F.softmax(out_i, dim=1),
F.softmax(out_m, dim=1),
)
pf_od, pi_od, pm_od = _per_eye_probs(x1, m1)
pf_os, pi_os, pm_os = _per_eye_probs(x2, m2)
if aggregate_patient:
y_chunks.append(y_t.cpu().numpy())
pf_chunks.append((0.5 * (pf_od + pf_os)).cpu().numpy())
pi_chunks.append((0.5 * (pi_od + pi_os)).cpu().numpy())
pm_chunks.append((0.5 * (pm_od + pm_os)).cpu().numpy())
else:
y_np = y_t.cpu().numpy()
y_chunks += [y_np, y_np]
pf_chunks += [pf_od.cpu().numpy(), pf_os.cpu().numpy()]
pi_chunks += [pi_od.cpu().numpy(), pi_os.cpu().numpy()]
pm_chunks += [pm_od.cpu().numpy(), pm_os.cpu().numpy()]
if not y_chunks:
z = np.zeros((0, 0), dtype=np.float32)
return np.array([], dtype=np.int64), z, z, z
return (
np.concatenate(y_chunks),
np.concatenate(pf_chunks, axis=0),
np.concatenate(pi_chunks, axis=0),
np.concatenate(pm_chunks, axis=0),
)
def collect_probs_bilateral_components(
model: BilateralHT,
loader: DataLoader,
device: torch.device,
) -> tuple[np.ndarray, np.ndarray, np.ndarray, np.ndarray]:
"""Collect fused/img/md probabilities for bilateral joint-tower model."""
model.eval()
y_chunks = []
pf_chunks, pi_chunks, pm_chunks = [], [], []
with torch.no_grad():
for batch in loader:
x1 = batch.get("image_1"); m1 = batch.get("matrix_1")
x2 = batch.get("image_2"); m2 = batch.get("matrix_2")
y = batch.get("label_1")
if not (torch.is_tensor(x1) and torch.is_tensor(m1) and torch.is_tensor(x2) and torch.is_tensor(m2)):
continue
y_t = _to_label_tensor(y, device)
joint_img, joint_md = model.encode_joint(
x1.to(device), m1.to(device), x2.to(device), m2.to(device)
)
out_f, _, _ = model.bridge(joint_img, joint_md)
out_i = model.aux_img(joint_img)
out_m = model.aux_md(joint_md)
y_chunks.append(y_t.cpu().numpy())
pf_chunks.append(F.softmax(out_f, dim=1).cpu().numpy())
pi_chunks.append(F.softmax(out_i, dim=1).cpu().numpy())
pm_chunks.append(F.softmax(out_m, dim=1).cpu().numpy())
if not y_chunks:
z = np.zeros((0, 0), dtype=np.float32)
return np.array([], dtype=np.int64), z, z, z
return (
np.concatenate(y_chunks),
np.concatenate(pf_chunks, axis=0),
np.concatenate(pi_chunks, axis=0),
np.concatenate(pm_chunks, axis=0),
)
# ---------------------------------------------------------------------------
# V2ModeComparisonOps — thin class wrapper kept for external import compat
# ---------------------------------------------------------------------------
class V2ModeComparisonOps:
"""Namespace wrapper kept for backward-compatibility imports."""
_set_requires_grad = staticmethod(_set_requires_grad)
_set_single_phase = staticmethod(_set_single_phase)
_set_bilateral_phase = staticmethod(_set_bilateral_phase)
train_single_epoch = staticmethod(train_single_epoch)
train_bilateral_epoch = staticmethod(train_bilateral_epoch)
collect_probs_classic = staticmethod(collect_probs_classic)
collect_probs_ensemble = staticmethod(collect_probs_ensemble)
collect_probs_bilateral = staticmethod(collect_probs_bilateral)
@staticmethod
def _to_label_tensor(labels, device: torch.device) -> torch.Tensor:
return _to_label_tensor(labels, device)