Agent Conversation: openai/gpt-5.4-pro

Model: openai/gpt-5.4-pro
Total steps: 6
Messages: 13
UserStep 0

Task: rl-offpolicy-continuous

Online RL: Off-Policy Actor-Critic for Continuous Control

Objective

Design and implement an off-policy actor-critic RL algorithm for continuous control. Your code goes in custom_offpolicy_continuous.py. Three reference implementations (DDPG, TD3, SAC) are provided as read-only.

Background

Off-policy methods maintain a replay buffer of past experience and update the policy using data collected under previous policies. Key challenges include overestimation bias in Q-value estimates, exploration-exploitation tradeoff, and sample efficiency. Different approaches address these through twin critics, entropy regularization, target smoothing, or delayed updates.

Constraints

  • Network architecture dimensions are FIXED and cannot be modified
  • Total parameter count is enforced at runtime
  • Focus on algorithmic innovation: new loss functions, update rules, exploration strategies, etc.
  • Do NOT simply copy a reference implementation with minor changes

Evaluation

Trained and evaluated on HalfCheetah-v4, Hopper-v4, Walker2d-v4. Additional held-out environments (not shown during intermediate testing) are used to assess generalization. Metric: mean episodic return over 10 evaluation episodes (higher is better).

cleanrl/cleanrl/custom_offpolicy_continuous.py [EDITABLE — lines 153–244 only]

     1: # Custom off-policy continuous RL algorithm for MLS-Bench
     2: #
     3: # EDITABLE section: Actor, QNetwork, and OffPolicyAlgorithm classes.
     4: # FIXED sections: everything else (config, env, buffer, eval, training loop).
     5: import os
     6: import random
     7: import time
     8: from dataclasses import dataclass
     9: 
    10: import gymnasium as gym
    11: import numpy as np
    12: import torch
    13: import torch.nn as nn
    14: import torch.nn.functional as F
    15: import torch.optim as optim
    16: import tyro
    17: 
    18: 
    19: # =====================================================================
    20: # FIXED: Configuration
    21: # =====================================================================
    22: @dataclass
    23: class Args:
    24:     exp_name: str = os.path.basename(__file__)[: -len(".py")]
    25:     """the name of this experiment"""
    26:     seed: int = 1
    27:     """seed of the experiment"""
    28:     torch_deterministic: bool = True
    29:     """if toggled, `torch.backends.cudnn.deterministic=False`"""
    30:     cuda: bool = True
    31:     """if toggled, cuda will be enabled by default"""
    32: 
    33:     # Algorithm specific arguments
    34:     env_id: str = "HalfCheetah-v4"
    35:     """the id of the environment"""
    36:     total_timesteps: int = 1000000
    37:     """total timesteps of the experiments"""
    38:     learning_rate: float = 3e-4
    39:     """the learning rate of the optimizer"""
    40:     buffer_size: int = int(1e6)
    41:     """the replay memory buffer size"""
    42:     gamma: floa
AssistantStep 1edit
Tool Input
1{
2  "op": "replace",
3  "filename": "cleanrl/cleanrl/custom_offpolicy_continuous.py",
4  "content": "class Actor(nn.Module):\n    \"\"\"Deterministic tanh actor used for training and evaluation.\"\"\"\n\n    def __init__(self, obs_dim, action_dim, max_action):\n        super().__init__()\n        self.max_action = max_action\n        self.fc1 = nn.Linear(obs_dim, 256)\n        self.fc2 = nn.Linear(256, 256)\n        self.fc_mu = nn.Linear(256, action_dim)\n        self.register_buffer(\"action_scale\", torch.tensor(max_action, dtype=torch.float32))\n\n    def forward(self, obs):\n        x = F.relu(self.fc1(obs))\n        x = F.relu(self.fc2(x))\n        return torch.tanh(self.fc_mu(x)) * self.action_scale\n\n    @torch.no_grad()\n    def get_action(self, obs):\n        return self.forward(obs)\n\n\nclass QNetwork(nn.Module):\n    \"\"\"Q-function Q(s, a) -> scalar.\"\"\"\n\n    def __init__(self, obs_dim, action_dim):\n        super().__init__()\n        self.fc1 = nn.Linear(obs_dim + action_dim, 256)\n        self.fc2 = nn.Linear(256, 256)\n        self.fc3 = nn.Linear(256, 1)\n\n    def forward(self, obs, action):\n        x = torch.cat([obs, action], dim=-1)\n        x = F.relu(self.fc1(x))\n        x = F.relu(self.fc2(x))\n        return self.fc3(x)\n\n\nclass OffPolicyAlgorithm:\n    \"\"\"UATD3: uncertainty-adaptive TD3 with gated behavior anchoring.\n\n    Core ideas:\n    1) Adaptive soft-clipped targets: interpolate between min and max target-Q only\n       when the critics agree, reducing TD3's underestimation while staying robust.\n    2) Advantage-gated anchoring: if replay actions look better than the current\n       policy at a state, softly pull the actor toward them; this fades over time.\n    3) Neighborhood policy improvement: optimize a blend of Q(pi) and Q(pi+eps)\n       to prefer actions that remain good under small perturbations.\n    \"\"\"\n\n    def __init__(self, obs_dim, action_dim, max_action, device, args):\n        self.device = device\n        self.max_action = max_action\n        self.gamma = args.gamma\n        self.tau = args.tau\n        self.exploration_noise = args.exploration_noise\n        self.policy_frequency = args.policy_frequency\n        self.policy_noise = 0.2\n        self.noise_clip = 0.5\n        self.target_mix = 0.25\n        self.actor_alpha = 2.5\n        self.anchor_decay = 200000.0\n        self.robust_noise = 0.05\n        self.total_it = 0\n        self.uncertainty_ema = 0.25\n\n        self.actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor.load_state_dict(self.actor.state_dict())\n\n        self.qf1 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target.load_state_dict(self.qf1.state_dict())\n        self.qf2_target.load_state_dict(self.qf2.state_dict())\n\n        self.actor_optimizer = optim.Adam(self.actor.parameters(), lr=args.learning_rate)\n        self.q_optimizer = optim.Adam(\n            list(self.qf1.parameters()) + list(self.qf2.parameters()), lr=args.learning_rate\n        )\n\n    def select_action(self, obs):\n        \"\"\"Exploration noise scales mildly with running critic disagreement.\"\"\"\n        obs_t = torch.tensor(obs.reshape(1, -1), device=self.device, dtype=torch.float32)\n        with torch.no_grad():\n            action = self.actor(obs_t).cpu().numpy().flatten()\n        noise_mult = float(np.clip(0.5 + 2.0 * self.uncertainty_ema, 0.5, 1.5))\n        noise = np.random.normal(\n            0.0, self.max_action * self.exploration_noise * noise_mult, size=action.shape\n        )\n        return np.clip(action + noise, -self.max_action, self.max_action)\n\n    def update(self, batch):\n        self.total_it += 1\n        obs, next_obs, actions, rewards, dones = batch\n\n        with torch.no_grad():\n            noise = (torch.randn_like(actions) * self.policy_noise).clamp(\n                -self.noise_clip, self.noise_clip\n            ) * self.max_action\n            next_actions = (self.target_actor(next_obs) + noise).clamp(\n                -self.max_action, self.max_action\n            )\n            target_q1 = self.qf1_target(next_obs, next_actions).view(-1)\n            target_q2 = self.qf2_target(next_obs, next_actions).view(-1)\n            q_min = torch.minimum(target_q1, target_q2)\n            q_max = torch.maximum(target_q1, target_q2)\n            gap = (target_q1 - target_q2).abs()\n            rel_gap = gap / (0.5 * (target_q1.abs() + target_q2.abs()) + 1.0)\n            trust = torch.exp(-rel_gap)\n            blended_target_q = q_min + self.target_mix * trust * (q_max - q_min)\n            td_target = rewards + (1 - dones) * self.gamma * blended_target_q\n\n        q1 = self.qf1(obs, actions).view(-1)\n        q2 = self.qf2(obs, actions).view(-1)\n        critic_loss = F.smooth_l1_loss(q1, td_target) + F.smooth_l1_loss(q2, td_target)\n\n        self.q_optimizer.zero_grad()\n        critic_loss.backward()\n        self.q_optimizer.step()\n\n        soft_update(self.qf1_target, self.qf1, self.tau)\n        soft_update(self.qf2_target, self.qf2, self.tau)\n        self.uncertainty_ema = 0.99 * self.uncertainty_ema + 0.01 * rel_gap.mean().item()\n\n        actor_loss_val = 0.0\n        anchor_loss_val = 0.0\n        if self.total_it % self.policy_frequency == 0:\n            pi = self.actor(obs)\n            q1_pi = self.qf1(obs, pi).view(-1)\n            q2_pi = self.qf2(obs, pi).view(-1)\n            q_pi = torch.minimum(q1_pi, q2_pi)\n\n            smooth_noise = (torch.randn_like(pi) * self.robust_noise).clamp(\n                -2 * self.robust_noise, 2 * self.robust_noise\n            ) * self.max_action\n            pi_perturbed = (pi + smooth_noise).clamp(-self.max_action, self.max_action)\n            q_pi_perturbed = torch.minimum(\n                self.qf1(obs, pi_perturbed), self.qf2(obs, pi_perturbed)\n            ).view(-1)\n            robust_q = 0.75 * q_pi + 0.25 * q_pi_perturbed\n\n            with torch.no_grad():\n                q_data = torch.minimum(self.qf1(obs, actions), self.qf2(obs, actions)).view(-1)\n                adv_gap = (q_data - q_pi.detach()) / (\n                    0.5 * (q_data.abs() + q_pi.detach().abs()) + 1.0\n                )\n                pi_rel_gap = (q1_pi.detach() - q2_pi.detach()).abs() / (\n                    0.5 * (q1_pi.detach().abs() + q2_pi.detach().abs()) + 1.0\n                )\n                anchor_weight = torch.sigmoid(4.0 * adv_gap) * (1.0 + pi_rel_gap)\n                anchor_scale = 1.0 / (1.0 + self.total_it / self.anchor_decay)\n\n            anchor_loss = (\n                anchor_weight * ((pi - actions) / self.max_action).pow(2).mean(dim=-1)\n            ).mean()\n            q_lambda = self.actor_alpha / (q_pi.detach().abs().mean() + 1e-6)\n            actor_loss = -q_lambda * robust_q.mean() + anchor_scale * anchor_loss\n\n            self.actor_optimizer.zero_grad()\n            actor_loss.backward()\n            self.actor_optimizer.step()\n            soft_update(self.target_actor, self.actor, self.tau)\n\n            actor_loss_val = actor_loss.item()\n            anchor_loss_val = anchor_loss.item()\n\n        return {\n            \"critic_loss\": critic_loss.item(),\n            \"actor_loss\": actor_loss_val,\n            \"anchor_loss\": anchor_loss_val,\n            \"uncertainty\": float(self.uncertainty_ema),\n        }\n",
5  "after_line": 244,
6  "start_line": 153,
7  "end_line": 244
8}
Tool ResultStep 1
OK: Replaced lines 153..244 with 173 line(s) in cleanrl/cleanrl/custom_offpolicy_continuous.py. Editable range: 153–325.

[Current file: cleanrl/cleanrl/custom_offpolicy_continuous.py | editable: 153–325 | total: 406 lines]
   150| # =====================================================================
   151| # EDITABLE: Network definitions and OffPolicyAlgorithm
   152| # =====================================================================
   153  class Actor(nn.Module):
   154      """Deterministic tanh actor used for training and evaluation."""
   155  
   156      def __init__(self, obs_dim, action_dim, max_action):
   157          super().__init__()
   158          self.max_action = max_action
   159          self.fc1 = nn.Linear(obs_dim, 256)
   160          self.fc2 = nn.Linear(256, 256)
   161          self.fc_mu = nn.Linear(256, action_dim)
   162          self.register_buffer("action_scale", torch.tensor(max_action, dtype=torch.float32))
   163  
   164      def forward(sel
AssistantStep 2test
Tool ResultStep 2
[Test #1] (2 tests remaining; call submit(n=1) to submit this result)


## Seed 42

### halfcheetah-v4 (scripts/halfcheetah.sh)
Training metrics (last steps):
TRAIN_METRICS step=896000 critic_loss=3.3085 actor_loss=-2.4938 anchor_loss=0.0231 uncertainty=0.0082
TRAIN_METRICS step=897000 critic_loss=3.9425 actor_loss=-2.4888 anchor_loss=0.0216 uncertainty=0.0083
TRAIN_METRICS step=898000 critic_loss=4.0854 actor_loss=-2.4902 anchor_loss=0.0206 uncertainty=0.0084
TRAIN_METRICS step=899000 critic_loss=4.0657 actor_loss=-2.4910 anchor_loss=0.0169 uncertainty=0.0081
TRAIN_METRICS step=900000 critic_loss=3.8973 actor_loss=-2.4900 anchor_loss=0.0226 uncertainty=0.0086
Evaluation (halfcheetah-v4):
Eval episodic_return: 4996.11
Eval episodic_return: 5909.64
Eval episodic_return: 4900.97
Final eval return: 4900.97

### reacher-v4 (scripts/reacher.sh)
Training metrics (last steps):
TRAIN_METRICS step=995000 critic_loss=0.0093 actor_loss=2.5010 anchor_loss=0.0036 uncertainty=0.0020
TRAIN_METRICS st
AssistantStep 3edit
Tool Input
1{
2  "op": "replace",
3  "filename": "cleanrl/cleanrl/custom_offpolicy_continuous.py",
4  "content": "class OffPolicyAlgorithm:\n    \"\"\"AW-TD3: Agreement-Weighted TD3.\n\n    Novel contribution: instead of always backing up with hard min(Q1, Q2), use an\n    agreement-weighted soft clip. When twin critics strongly agree, we move the\n    target and actor objective slightly above the TD3 minimum to reduce systematic\n    underestimation; when they disagree, we recover the conservative TD3 backup.\n    \"\"\"\n\n    def __init__(self, obs_dim, action_dim, max_action, device, args):\n        self.device = device\n        self.max_action = max_action\n        self.gamma = args.gamma\n        self.tau = args.tau\n        self.exploration_noise = args.exploration_noise\n        self.policy_frequency = args.policy_frequency\n        self.policy_noise = 0.2\n        self.noise_clip = 0.5\n        self.target_mix = 0.4\n        self.actor_mix = 0.3\n        self.agreement_temp = 2.0\n        self.total_it = 0\n\n        self.actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor.load_state_dict(self.actor.state_dict())\n\n        self.qf1 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target.load_state_dict(self.qf1.state_dict())\n        self.qf2_target.load_state_dict(self.qf2.state_dict())\n\n        self.actor_optimizer = optim.Adam(self.actor.parameters(), lr=args.learning_rate)\n        self.q_optimizer = optim.Adam(\n            list(self.qf1.parameters()) + list(self.qf2.parameters()), lr=args.learning_rate\n        )\n\n    def _agreement_blend(self, q1, q2, mix):\n        q_min = torch.minimum(q1, q2)\n        q_max = torch.maximum(q1, q2)\n        rel_gap = (q1 - q2).abs() / (0.5 * (q1.abs() + q2.abs()) + 1.0)\n        agreement = torch.exp(-self.agreement_temp * rel_gap)\n        soft_q = q_min + mix * agreement * (q_max - q_min)\n        return soft_q, agreement\n\n    def select_action(self, obs):\n        obs_t = torch.tensor(obs.reshape(1, -1), device=self.device, dtype=torch.float32)\n        with torch.no_grad():\n            action = self.actor(obs_t).cpu().numpy().flatten()\n        noise = np.random.normal(0, self.max_action * self.exploration_noise, size=action.shape)\n        return np.clip(action + noise, -self.max_action, self.max_action)\n\n    def update(self, batch):\n        self.total_it += 1\n        obs, next_obs, actions, rewards, dones = batch\n\n        with torch.no_grad():\n            noise = (torch.randn_like(actions) * self.policy_noise).clamp(\n                -self.noise_clip, self.noise_clip\n            ) * self.max_action\n            next_actions = (self.target_actor(next_obs) + noise).clamp(\n                -self.max_action, self.max_action\n            )\n            target_q1 = self.qf1_target(next_obs, next_actions).view(-1)\n            target_q2 = self.qf2_target(next_obs, next_actions).view(-1)\n            target_q, target_agreement = self._agreement_blend(\n                target_q1, target_q2, self.target_mix\n            )\n            td_target = rewards + (1 - dones) * self.gamma * target_q\n\n        q1 = self.qf1(obs, actions).view(-1)\n        q2 = self.qf2(obs, actions).view(-1)\n        critic_loss = F.mse_loss(q1, td_target) + F.mse_loss(q2, td_target)\n\n        self.q_optimizer.zero_grad()\n        critic_loss.backward()\n        self.q_optimizer.step()\n\n        actor_loss_val = 0.0\n        actor_agreement_val = 0.0\n        if self.total_it % self.policy_frequency == 0:\n            pi = self.actor(obs)\n            q1_pi = self.qf1(obs, pi).view(-1)\n            q2_pi = self.qf2(obs, pi).view(-1)\n            actor_q, actor_agreement = self._agreement_blend(q1_pi, q2_pi, self.actor_mix)\n            actor_loss = -actor_q.mean()\n\n            self.actor_optimizer.zero_grad()\n            actor_loss.backward()\n            self.actor_optimizer.step()\n\n            soft_update(self.qf1_target, self.qf1, self.tau)\n            soft_update(self.qf2_target, self.qf2, self.tau)\n            soft_update(self.target_actor, self.actor, self.tau)\n\n            actor_loss_val = actor_loss.item()\n            actor_agreement_val = actor_agreement.mean().item()\n\n        return {\n            \"critic_loss\": critic_loss.item(),\n            \"actor_loss\": actor_loss_val,\n            \"target_agreement\": target_agreement.mean().item(),\n            \"actor_agreement\": actor_agreement_val,\n        }\n",
5  "after_line": 325,
6  "start_line": 190,
7  "end_line": 325
8}
Tool ResultStep 3
OK: Replaced lines 190..325 with 106 line(s) in cleanrl/cleanrl/custom_offpolicy_continuous.py. Editable range: 153–295.

[Current file: cleanrl/cleanrl/custom_offpolicy_continuous.py | editable: 153–295 | total: 376 lines]
   150| # =====================================================================
   151| # EDITABLE: Network definitions and OffPolicyAlgorithm
   152| # =====================================================================
   153  class Actor(nn.Module):
   154      """Deterministic tanh actor used for training and evaluation."""
   155  
   156      def __init__(self, obs_dim, action_dim, max_action):
   157          super().__init__()
   158          self.max_action = max_action
   159          self.fc1 = nn.Linear(obs_dim, 256)
   160          self.fc2 = nn.Linear(256, 256)
   161          self.fc_mu = nn.Linear(256, action_dim)
   162          self.register_buffer("action_scale", torch.tensor(max_action, dtype=torch.float32))
   163  
   164      def forward(sel
AssistantStep 4test
Tool ResultStep 4
[Test #2] (1 test remaining; call submit(n=2) to submit this result)

### halfcheetah-v4 (scripts/halfcheetah.sh)
Training metrics (last steps):
TRAIN_METRICS step=85000 critic_loss=11.9597 actor_loss=-146.3225 target_agreement=0.9478 actor_agreement=0.9483
TRAIN_METRICS step=86000 critic_loss=12.4670 actor_loss=-152.5188 target_agreement=0.9568 actor_agreement=0.9566
TRAIN_METRICS step=87000 critic_loss=13.4277 actor_loss=-154.7044 target_agreement=0.9572 actor_agreement=0.9539
TRAIN_METRICS step=88000 critic_loss=23.2070 actor_loss=-158.5827 target_agreement=0.9558 actor_agreement=0.9575
TRAIN_METRICS step=89000 critic_loss=13.0975 actor_loss=-164.4578 target_agreement=0.9624 actor_agreement=0.9644
Evaluation (halfcheetah-v4):
Eval episodic_return: 2475.02
Eval episodic_return: 3220.57
Eval episodic_return: 1869.43
Final eval return: 1869.43

### reacher-v4 (scripts/reacher.sh)
Training metrics (last steps):
TRAIN_METRICS step=95000 critic_loss=0.0318 actor_loss=10.8688 target_agreem
AssistantStep 5edit
Tool Input
1{
2  "op": "replace",
3  "filename": "cleanrl/cleanrl/custom_offpolicy_continuous.py",
4  "content": "class OffPolicyAlgorithm:\n    \"\"\"Soft-Clipped Policy TD3.\n\n    Novel contribution: keep the standard TD3 critic target, but replace the actor\n    update with a soft-clipped double-Q objective. The policy maximizes a convex\n    combination of min(Q1, Q2) and max(Q1, Q2), which is equivalent to maximizing\n    the average value while applying an implicit disagreement penalty. This keeps\n    the TD3 safety benefits while reducing sensitivity to a single critic's errors.\n    \"\"\"\n\n    def __init__(self, obs_dim, action_dim, max_action, device, args):\n        self.device = device\n        self.max_action = max_action\n        self.gamma = args.gamma\n        self.tau = args.tau\n        self.exploration_noise = args.exploration_noise\n        self.policy_frequency = args.policy_frequency\n        self.policy_noise = 0.2\n        self.noise_clip = 0.5\n        self.actor_mix = 0.25\n        self.total_it = 0\n\n        self.actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor = Actor(obs_dim, action_dim, max_action).to(device)\n        self.target_actor.load_state_dict(self.actor.state_dict())\n\n        self.qf1 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2 = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf2_target = QNetwork(obs_dim, action_dim).to(device)\n        self.qf1_target.load_state_dict(self.qf1.state_dict())\n        self.qf2_target.load_state_dict(self.qf2.state_dict())\n\n        self.actor_optimizer = optim.Adam(self.actor.parameters(), lr=args.learning_rate)\n        self.q_optimizer = optim.Adam(\n            list(self.qf1.parameters()) + list(self.qf2.parameters()),\n            lr=args.learning_rate,\n        )\n\n    def _soft_clipped(self, q1, q2, mix):\n        q_min = torch.minimum(q1, q2)\n        q_max = torch.maximum(q1, q2)\n        return q_min + mix * (q_max - q_min)\n\n    def select_action(self, obs):\n        obs_t = torch.tensor(obs.reshape(1, -1), device=self.device, dtype=torch.float32)\n        with torch.no_grad():\n            action = self.actor(obs_t).cpu().numpy().flatten()\n        noise = np.random.normal(0, self.max_action * self.exploration_noise, size=action.shape)\n        return np.clip(action + noise, -self.max_action, self.max_action)\n\n    def update(self, batch):\n        self.total_it += 1\n        obs, next_obs, actions, rewards, dones = batch\n\n        with torch.no_grad():\n            noise = (torch.randn_like(actions) * self.policy_noise).clamp(\n                -self.noise_clip, self.noise_clip\n            ) * self.max_action\n            next_actions = (self.target_actor(next_obs) + noise).clamp(\n                -self.max_action, self.max_action\n            )\n            target_q1 = self.qf1_target(next_obs, next_actions).view(-1)\n            target_q2 = self.qf2_target(next_obs, next_actions).view(-1)\n            td_target = rewards + (1 - dones) * self.gamma * torch.min(target_q1, target_q2)\n\n        q1 = self.qf1(obs, actions).view(-1)\n        q2 = self.qf2(obs, actions).view(-1)\n        critic_loss = F.mse_loss(q1, td_target) + F.mse_loss(q2, td_target)\n\n        self.q_optimizer.zero_grad()\n        critic_loss.backward()\n        self.q_optimizer.step()\n\n        actor_loss_val = 0.0\n        disagreement_val = 0.0\n        if self.total_it % self.policy_frequency == 0:\n            pi = self.actor(obs)\n            q1_pi = self.qf1(obs, pi).view(-1)\n            q2_pi = self.qf2(obs, pi).view(-1)\n            actor_q = self._soft_clipped(q1_pi, q2_pi, self.actor_mix)\n            actor_loss = -actor_q.mean()\n\n            self.actor_optimizer.zero_grad()\n            actor_loss.backward()\n            self.actor_optimizer.step()\n\n            soft_update(self.qf1_target, self.qf1, self.tau)\n            soft_update(self.qf2_target, self.qf2, self.tau)\n            soft_update(self.target_actor, self.actor, self.tau)\n\n            actor_loss_val = actor_loss.item()\n            disagreement_val = (q1_pi - q2_pi).abs().mean().item()\n\n        return {\n            \"critic_loss\": critic_loss.item(),\n            \"actor_loss\": actor_loss_val,\n            \"critic_disagreement\": disagreement_val,\n        }\n",
5  "after_line": 295,
6  "start_line": 190,
7  "end_line": 295
8}
Tool ResultStep 5
OK: Replaced lines 190..295 with 99 line(s) in cleanrl/cleanrl/custom_offpolicy_continuous.py. Editable range: 153–288.

[Current file: cleanrl/cleanrl/custom_offpolicy_continuous.py | editable: 153–288 | total: 369 lines]
   150| # =====================================================================
   151| # EDITABLE: Network definitions and OffPolicyAlgorithm
   152| # =====================================================================
   153  class Actor(nn.Module):
   154      """Deterministic tanh actor used for training and evaluation."""
   155  
   156      def __init__(self, obs_dim, action_dim, max_action):
   157          super().__init__()
   158          self.max_action = max_action
   159          self.fc1 = nn.Linear(obs_dim, 256)
   160          self.fc2 = nn.Linear(256, 256)
   161          self.fc_mu = nn.Linear(256, action_dim)
   162          self.register_buffer("action_scale", torch.tensor(max_action, dtype=torch.float32))
   163  
   164      def forward(self
AssistantStep 6test
Tool ResultStep 6
[Test #3] (0 tests remaining)


## Seed 42

### halfcheetah-v4 (scripts/halfcheetah.sh)
Training metrics (last steps):
TRAIN_METRICS step=766000 critic_loss=26.8812 actor_loss=-739.4603 critic_disagreement=1.6009
TRAIN_METRICS step=767000 critic_loss=29.5062 actor_loss=-742.9932 critic_disagreement=1.7002
TRAIN_METRICS step=768000 critic_loss=28.6160 actor_loss=-739.6460 critic_disagreement=1.5442
TRAIN_METRICS step=769000 critic_loss=34.4093 actor_loss=-734.1824 critic_disagreement=1.5390
TRAIN_METRICS step=770000 critic_loss=27.3246 actor_loss=-732.7402 critic_disagreement=1.6616
Evaluation (halfcheetah-v4):
Eval episodic_return: 10255.59
Eval episodic_return: 10060.25
Eval episodic_return: 10150.78
Final eval return: 10150.78

### reacher-v4 (scripts/reacher.sh)
Training metrics (last steps):
TRAIN_METRICS step=875000 critic_loss=0.0231 actor_loss=12.5891 critic_disagreement=0.0201
TRAIN_METRICS step=876000 critic_loss=0.0183 actor_loss=12.5299 critic_disagreement=0.0213
TRAIN_METRI