feat: add held-out validation and dual-decoder lewm imf

tests/test_imf_vla_agent.py

@@ -388,6 +388,26 @@ class _StubFutureTokenPredictor(nn.Module):
         return summary.repeat(1, self.num_future_tokens, 1)
 
 
+class _RecordingDirectFutureDecoder(nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.scale = nn.Parameter(torch.tensor(0.5))
+        self.calls = []
+
+    def forward(self, sample, r, t, cond=None):
+        record = {
+            'sample': sample.detach().clone(),
+            'r': r.detach().clone(),
+            't': t.detach().clone(),
+            'cond': None if cond is None else cond.detach().clone(),
+        }
+        self.calls.append(record)
+        cond_term = 0.0
+        if cond is not None:
+            cond_term = cond.mean(dim=1, keepdim=True)
+        return self.scale * sample + cond_term
+
+
 class _RecordingSigReg(nn.Module):
     def __init__(self, value=0.5):
         super().__init__()
@@ -687,6 +707,148 @@ class IMFVLAAgentTest(unittest.TestCase):
         )
         torch.testing.assert_close(sigreg.calls[0], expected_lewm_history.transpose(0, 1))
 
+    def test_predict_action_with_dual_decoder_keeps_action_condition_history_only(self):
+        agent_cls, agent_module = _load_imf_agent_class()
+        head = _RecordingLinearIMFHead()
+        future_decoder = _RecordingDirectFutureDecoder()
+        agent = agent_cls(
+            vision_backbone=_StubVisionBackbone(),
+            state_encoder=nn.Identity(),
+            action_encoder=nn.Identity(),
+            head=head,
+            future_decoder=future_decoder,
+            action_dim=2,
+            obs_dim=1,
+            pred_horizon=3,
+            obs_horizon=2,
+            diffusion_steps=10,
+            inference_steps=1,
+            num_cams=len(_CAMERA_NAMES),
+            camera_names=_CAMERA_NAMES,
+            num_action_steps=2,
+            head_type='transformer',
+            lewm_history_horizon=3,
+            lewm_query_offsets=[8],
+            lewm_loss_weight=1.0,
+        )
+        agent.infer_scheduler = _ForbiddenScheduler()
+        with torch.no_grad():
+            agent.future_query_tokens.copy_(torch.tensor([[[0.1, 0.2, 0.3, 0.4]]], dtype=torch.float32))
+
+        images = _make_images(
+            batch_size=1,
+            obs_horizon=2,
+            per_camera_fill={'r_vis': 10.0, 'top': 20.0, 'front': 30.0},
+        )
+        qpos = torch.tensor([[[1.0], [2.0]]], dtype=torch.float32)
+        initial_noise = torch.tensor(
+            [[[1.0, -1.0], [0.0, 2.0], [3.0, -2.0]]],
+            dtype=torch.float32,
+        )
+
+        with mock.patch.object(agent_module.torch, 'randn', return_value=initial_noise):
+            _ = agent.predict_action(images, qpos)
+
+        expected_history = torch.tensor(
+            [[[10.0, 20.0, 30.0, 1.0], [10.0, 20.0, 30.0, 2.0]]],
+            dtype=torch.float32,
+        )
+        self.assertEqual(len(head.calls), 1)
+        self.assertTrue(torch.allclose(head.calls[0]['cond'], expected_history))
+        self.assertEqual(len(future_decoder.calls), 0)
+
+    def test_compute_loss_with_dual_decoder_tracks_lewm_loss_breakdown(self):
+        agent_cls, agent_module = _load_imf_agent_class()
+        head = _RecordingLinearIMFHead()
+        future_decoder = _RecordingDirectFutureDecoder()
+        sigreg = _RecordingSigReg(value=0.75)
+        agent = agent_cls(
+            vision_backbone=_StubVisionBackbone(),
+            state_encoder=nn.Identity(),
+            action_encoder=nn.Identity(),
+            head=head,
+            future_decoder=future_decoder,
+            action_dim=2,
+            obs_dim=1,
+            pred_horizon=3,
+            obs_horizon=2,
+            diffusion_steps=10,
+            inference_steps=1,
+            num_cams=len(_CAMERA_NAMES),
+            camera_names=_CAMERA_NAMES,
+            num_action_steps=2,
+            head_type='transformer',
+            lewm_history_horizon=3,
+            lewm_query_offsets=[8],
+            lewm_sigreg=sigreg,
+            lewm_sigreg_weight=0.09,
+            lewm_loss_weight=1.0,
+        )
+        with torch.no_grad():
+            agent.future_query_tokens.copy_(torch.tensor([[[0.2, 0.4, 0.6, 0.8]]], dtype=torch.float32))
+
+        images = _make_images(
+            batch_size=1,
+            obs_horizon=2,
+            per_camera_fill={'r_vis': 1.0, 'top': 2.0, 'front': 3.0},
+        )
+        qpos = torch.tensor([[[0.25], [0.75]]], dtype=torch.float32)
+        actions = torch.tensor(
+            [[[1.0, -1.0], [0.5, 0.25], [-0.5, 1.5]]],
+            dtype=torch.float32,
+        )
+        lewm_images = _make_images(
+            batch_size=1,
+            obs_horizon=3,
+            per_camera_fill={'r_vis': 1.0, 'top': 2.0, 'front': 3.0},
+        )
+        lewm_qpos = torch.tensor([[[0.1], [0.2], [0.3]]], dtype=torch.float32)
+        lewm_future_images = _make_images(
+            batch_size=1,
+            obs_horizon=1,
+            per_camera_fill={'r_vis': 1.0, 'top': 2.0, 'front': 3.0},
+        )
+        lewm_future_qpos = torch.tensor([[[0.4]]], dtype=torch.float32)
+        noise = torch.tensor(
+            [[[0.2, -0.4], [0.1, 0.3], [0.5, -0.2]]],
+            dtype=torch.float32,
+        )
+        t_sample = torch.tensor([0.8], dtype=torch.float32)
+        r_sample = torch.tensor([0.25], dtype=torch.float32)
+
+        with mock.patch.object(agent_module.torch, 'randn_like', return_value=noise), \
+             mock.patch.object(agent_module.torch, 'rand', side_effect=[t_sample, r_sample]):
+            loss = agent.compute_loss(
+                {
+                    'images': images,
+                    'qpos': qpos,
+                    'action': actions,
+                    'lewm_images': lewm_images,
+                    'lewm_qpos': lewm_qpos,
+                    'lewm_future_images': lewm_future_images,
+                    'lewm_future_qpos': lewm_future_qpos,
+                }
+            )
+
+        metrics = agent.get_last_loss_breakdown()
+        self.assertAlmostEqual(loss.item(), metrics['loss'], places=6)
+        self.assertEqual(len(head.calls), 2)
+        self.assertEqual(head.calls[0]['cond'].shape, (1, 2, 4))
+        self.assertEqual(len(future_decoder.calls), 1)
+        self.assertEqual(future_decoder.calls[0]['cond'].shape, (1, 3, 4))
+        self.assertAlmostEqual(
+            metrics['loss'],
+            metrics['action_loss'] + metrics['lewm_loss'],
+            places=5,
+        )
+        self.assertAlmostEqual(
+            metrics['lewm_loss'],
+            metrics['lewm_pred_loss'] + 0.09 * metrics['lewm_sigreg_loss'],
+            places=5,
+        )
+        self.assertGreater(metrics['lewm_pred_loss'], 0.0)
+        self.assertAlmostEqual(metrics['lewm_sigreg_loss'], 0.75, places=6)
+
     def test_select_action_only_regenerates_when_action_queue_is_empty(self):
         agent, _head, _agent_module = self._make_agent(pred_horizon=4, obs_horizon=2, num_action_steps=2)
         observation = {
@@ -1077,6 +1239,36 @@ class IMFVLAAgentTest(unittest.TestCase):
         )
         self.assertIsNotNone(agent.lewm_sigreg)
 
+    def test_hydra_config_instantiates_lewm_resnet_dual_decoder_imf_attnres(self):
+        cfg = _compose_cfg(
+            overrides=[
+                'agent=lewm_resnet_dual_decoder_imf_attnres',
+                'agent.head.n_layer=1',
+                'agent.head.n_emb=16',
+                'agent.future_decoder.n_layer=1',
+                'agent.future_decoder.n_emb=16',
+                'agent.lewm_query_offsets=[8]',
+            ]
+        )
+
+        self.assertEqual(cfg.agent._target_, 'roboimi.vla.agent_imf.IMFVLAAgent')
+        self.assertEqual(cfg.agent.extra_condition_tokens, 0)
+        self.assertEqual(
+            cfg.agent.future_decoder._target_,
+            'roboimi.vla.models.heads.imf_transformer1d.IMFTransformer1D',
+        )
+        self.assertEqual(cfg.agent.head.cond_dim, 288)
+        self.assertEqual(cfg.agent.future_decoder.cond_dim, 288)
+
+        with _stub_optional_modules(include_imf_head=True):
+            agent = instantiate(cfg.agent)
+
+        self.assertEqual(agent.per_step_cond_dim, 288)
+        self.assertEqual(agent.condition_sequence_length, agent.obs_horizon)
+        self.assertEqual(agent.noise_pred_net.constructor_kwargs['n_obs_steps'], agent.obs_horizon)
+        self.assertEqual(agent.future_decoder.constructor_kwargs['cond_dim'], 288)
+        self.assertEqual(agent.future_query_tokens.shape, (1, 1, 288))
+
 
     def test_hydra_config_instantiates_resnet_imf_attnres_multitoken_with_sequence_length_three_times_obs_horizon(self):
         cfg = _compose_cfg(