DPI/train.py

@@ -1,12 +1,15 @@
+import numpy as np
+import torch
+import argparse
 import os
-import gc 
+import gym
+import time
+import json
+import dmc2gym
+
 import copy
 import tqdm
 import wandb
-import random
-import argparse
-import numpy as np
-
 import utils
 from utils import ReplayBuffer, FreezeParameters, make_env, preprocess_obs, soft_update_params, save_image
 from models import ObservationEncoder, ObservationDecoder, TransitionModel, Actor, ValueModel, RewardModel, ProjectionHead, ContrastiveHead, CLUBSample
@@ -14,12 +17,13 @@ from logger import Logger
 from video import VideoRecorder
 from dmc2gym.wrappers import set_global_var
 
-import torch
 import torch.nn as nn
 import torch.nn.functional as F
 import torchvision.transforms as T
 from torch.utils.tensorboard import SummaryWriter
 
+
+
 #from agent.baseline_agent import BaselineAgent
 #from agent.bisim_agent import BisimAgent
 #from agent.deepmdp_agent import DeepMDPAgent
@@ -34,9 +38,8 @@ def parse_args():
     parser.add_argument('--task_name', default='run')
     parser.add_argument('--image_size', default=84, type=int)
     parser.add_argument('--channels', default=3, type=int)
-    parser.add_argument('--action_repeat', default=2, type=int)
+    parser.add_argument('--action_repeat', default=1, type=int)
     parser.add_argument('--frame_stack', default=3, type=int)
-    parser.add_argument('--collection_interval', default=100, type=int)
     parser.add_argument('--resource_files', type=str)
     parser.add_argument('--eval_resource_files', type=str)
     parser.add_argument('--img_source', default=None, type=str, choices=['color', 'noise', 'images', 'video', 'none'])
@@ -49,11 +52,11 @@ def parse_args():
     parser.add_argument('--agent', default='dpi', type=str, choices=['baseline', 'bisim', 'deepmdp', 'db', 'dpi', 'rpc'])
     parser.add_argument('--init_steps', default=10000, type=int)
     parser.add_argument('--num_train_steps', default=10000, type=int)
-    parser.add_argument('--batch_size', default=30, type=int)  #512
+    parser.add_argument('--batch_size', default=20, type=int)  #512
     parser.add_argument('--state_size', default=256, type=int)
     parser.add_argument('--hidden_size', default=128, type=int)
     parser.add_argument('--history_size', default=128, type=int)
-    parser.add_argument('--num-units', type=int, default=50, help='num hidden units for reward/value/discount models')
+    parser.add_argument('--num-units', type=int, default=200, help='num hidden units for reward/value/discount models')
     parser.add_argument('--load_encoder', default=None, type=str)
     parser.add_argument('--imagine_horizon', default=15, type=str)
     parser.add_argument('--grad_clip_norm', type=float, default=100.0, help='Gradient clipping norm')
@@ -61,13 +64,15 @@ def parse_args():
     parser.add_argument('--eval_freq', default=10, type=int)  # TODO: master had 10000
     parser.add_argument('--num_eval_episodes', default=20, type=int)
     # value
-    parser.add_argument('--value_lr', default=8e-5, type=float)
+    parser.add_argument('--value_lr', default=1e-4, type=float)
     parser.add_argument('--value_beta', default=0.9, type=float)
     parser.add_argument('--value_tau', default=0.005, type=float)
     parser.add_argument('--value_target_update_freq', default=100, type=int)
     parser.add_argument('--td_lambda', default=0.95, type=int)
+    # reward
+    parser.add_argument('--reward_lr', default=1e-4, type=float)
     # actor
-    parser.add_argument('--actor_lr', default=8e-5, type=float)
+    parser.add_argument('--actor_lr', default=1e-4, type=float)
     parser.add_argument('--actor_beta', default=0.9, type=float)
     parser.add_argument('--actor_log_std_min', default=-10, type=float)
     parser.add_argument('--actor_log_std_max', default=2, type=float)
@@ -75,7 +80,7 @@ def parse_args():
     # world/encoder/decoder
     parser.add_argument('--encoder_type', default='pixel', type=str, choices=['pixel', 'pixelCarla096', 'pixelCarla098', 'identity'])
     parser.add_argument('--encoder_feature_dim', default=50, type=int)
-    parser.add_argument('--world_model_lr', default=6e-4, type=float)
+    parser.add_argument('--world_model_lr', default=1e-3, type=float)
     parser.add_argument('--past_transition_lr', default=1e-3, type=float)
     parser.add_argument('--encoder_lr', default=1e-3, type=float)
     parser.add_argument('--encoder_tau', default=0.001, type=float)
@@ -95,7 +100,6 @@ def parse_args():
     # misc
     parser.add_argument('--seed', default=1, type=int)
     parser.add_argument('--logging_freq', default=100, type=int)
-    parser.add_argument('--saving_interval', default=1000, type=int)
     parser.add_argument('--work_dir', default='.', type=str)
     parser.add_argument('--save_tb', default=False, action='store_true')
     parser.add_argument('--save_model', default=False, action='store_true')
@@ -103,6 +107,8 @@ def parse_args():
     parser.add_argument('--save_video', default=False, action='store_true')
     parser.add_argument('--transition_model_type', default='', type=str, choices=['', 'deterministic', 'probabilistic', 'ensemble'])
     parser.add_argument('--render', default=False, action='store_true')
+    parser.add_argument('--port', default=2000, type=int)
+    parser.add_argument('--num_likelihood_updates', default=5, type=int)
     args = parser.parse_args()
     return args
 
@@ -113,7 +119,7 @@ def parse_args():
 
 
 class DPI:
-    def __init__(self, args):
+    def __init__(self, args, writer):
         # wandb config
         #run = wandb.init(project="dpi")
     
@@ -135,8 +141,6 @@ class DPI:
         # stack several consecutive frames together
         if self.args.encoder_type.startswith('pixel'):
             self.env = utils.FrameStack(self.env, k=self.args.frame_stack)
-            self.env = utils.ActionRepeat(self.env, self.args.action_repeat)
-            self.env = utils.NormalizeActions(self.env)
 
         # create replay buffer
         self.data_buffer = ReplayBuffer(size=self.args.replay_buffer_capacity, 
@@ -160,64 +164,64 @@ class DPI:
         self.obs_encoder = ObservationEncoder(
                             obs_shape=(self.args.frame_stack*self.args.channels,self.args.image_size,self.args.image_size), # (9,84,84)
                             state_size=self.args.state_size # 128
-                            ).to(device)
+                            )
         
         self.obs_encoder_momentum = ObservationEncoder(
                             obs_shape=(self.args.frame_stack*self.args.channels,self.args.image_size,self.args.image_size), # (9,84,84)
                             state_size=self.args.state_size # 128
-                            ).to(device)
+                            )
 
         self.obs_decoder = ObservationDecoder(
                             state_size=self.args.state_size, # 128
                             output_shape=(self.args.channels,self.args.image_size,self.args.image_size) # (3,84,84)
-                            ).to(device)
+                            )
 
         self.transition_model = TransitionModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
                             action_size=self.env.action_space.shape[0], # 6
                             history_size=self.args.history_size, # 128
-                            ).to(device)
+                            )
         
         # Actor Model
         self.actor_model = Actor(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256, 
                             action_size=self.env.action_space.shape[0], # 6
-                            ).to(device)
+                            )
         
         # Value Models
         self.value_model = ValueModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
         
         self.target_value_model = ValueModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
 
         self.reward_model = RewardModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
         
         # Contrastive Models
         self.prjoection_head = ProjectionHead(
                             state_size=self.args.state_size, # 128
                             action_size=self.env.action_space.shape[0], # 6
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
         
         self.prjoection_head_momentum = ProjectionHead(
                             state_size=self.args.state_size, # 128
                             action_size=self.env.action_space.shape[0], # 6
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
         
         self.contrastive_head = ContrastiveHead(
                             hidden_size=self.args.hidden_size, # 256
-                            ).to(device)
+                            )
 
 
         # model parameters
@@ -233,7 +237,7 @@ class DPI:
         self.past_transition_opt = torch.optim.Adam(self.past_transition_parameters, self.args.past_transition_lr)
 
         # Create Modules
-        self.world_model_modules = [self.obs_encoder, self.obs_decoder, self.reward_model, self.transition_model, self.prjoection_head]
+        self.world_model_modules = [self.obs_encoder, self.obs_decoder, self.value_model, self.transition_model, self.prjoection_head]
         self.value_modules = [self.value_model]
         self.actor_modules = [self.actor_model]
 
@@ -245,27 +249,21 @@ class DPI:
         self.obs_decoder.load_state_dict(torch.load(os.path.join(saved_model_dir, 'obs_decoder.pt')))
         self.transition_model.load_state_dict(torch.load(os.path.join(saved_model_dir, 'transition_model.pt')))
 
-    def collect_sequences(self, episodes,  random=True, actor_model=None, encoder_model=None):
+    def collect_sequences(self, episodes):
         obs = self.env.reset()
         done = False
 
-        all_rews = []
         #video = VideoRecorder(self.video_dir if args.save_video else None, resource_files=args.resource_files)
         for episode_count in tqdm.tqdm(range(episodes), desc='Collecting episodes'):
             if args.save_video:
                 self.env.video.init(enabled=True)
 
-            epi_reward = 0
             for i in range(self.args.episode_length):
-                if random:
+                
                 action = self.env.action_space.sample()
-                else:
-                    with torch.no_grad():
-                        obs_torch = torch.unsqueeze(torch.tensor(obs).float(),0).to(device)
-                        state = self.obs_encoder(obs_torch)["distribution"].sample()
-                        action = self.actor_model(state).cpu().detach().numpy().squeeze()
 
                 next_obs, rew, done, _ = self.env.step(action)
+
                 self.data_buffer.add(obs, action, next_obs, rew, episode_count+1, done)
                 
                 if args.save_video:
@@ -276,50 +274,36 @@ class DPI:
                     done=False
                 else:
                     obs = next_obs
-                epi_reward += rew
-            all_rews.append(epi_reward)
             if args.save_video:
                 self.env.video.save('noisy/%d.mp4' % episode_count)
         print("Collected {} random episodes".format(episode_count+1))
-        return all_rews
-
-    def train(self, step, total_steps):
-        counter = 0
-        while step < total_steps:
 
+    def train(self):
         # collect experience
-            if step !=0:
+        self.collect_sequences(self.args.batch_size)
-                encoder = self.obs_encoder
-                actor = self.actor_model
-                #all_rews = self.collect_sequences(self.args.batch_size, random=True)
-                all_rews = self.collect_sequences(self.args.batch_size, random=False, actor_model=actor, encoder_model=encoder)
-            else:
-                all_rews = self.collect_sequences(self.args.batch_size, random=True)
 
-            # Group by steps and sample random batch
+        # Group observations and next_observations by steps from past to present
-            random_indices = self.data_buffer.sample_random_idx(self.args.batch_size * ((step//self.args.collection_interval)+1))  # random indices for batch
+        last_observations = torch.tensor(self.data_buffer.group_steps(self.data_buffer,"observations")).float()[:self.args.episode_length-1]
-            #random_indices = np.arange(self.args.batch_size * ((step//self.args.collection_interval)),self.args.batch_size * ((step//self.args.collection_interval)+1))
+        current_observations = torch.Tensor(self.data_buffer.group_steps(self.data_buffer,"next_observations")).float()[:self.args.episode_length-1]
-            last_observations = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"observations", "cpu", random_indices=random_indices)
+        next_observations = torch.Tensor(self.data_buffer.group_steps(self.data_buffer,"next_observations")).float()[1:]
-            current_observations = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"next_observations", device="cpu", random_indices=random_indices)
+        actions = torch.Tensor(self.data_buffer.group_steps(self.data_buffer,"actions",obs=False)).float()[:self.args.episode_length-1]
-            next_observations = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"next_observations", device="cpu", offset=1, random_indices=random_indices)
+        next_actions = torch.Tensor(self.data_buffer.group_steps(self.data_buffer,"actions",obs=False)).float()[1:]
-            actions = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"actions", device=device, is_obs=False, random_indices=random_indices)
+        rewards = torch.Tensor(self.data_buffer.group_steps(self.data_buffer,"rewards",obs=False)).float()[1:]
-            next_actions = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"actions", device=device, is_obs=False, offset=1, random_indices=random_indices)
-            rewards = self.data_buffer.group_and_sample_random_batch(self.data_buffer,"rewards", device=device, is_obs=False, offset=1, random_indices=random_indices)
         
         # Preprocessing
-            last_observations = preprocess_obs(last_observations).to(device)
+        last_observations = preprocess_obs(last_observations)
-            current_observations = preprocess_obs(current_observations).to(device)
+        current_observations = preprocess_obs(current_observations)
-            next_observations = preprocess_obs(next_observations).to(device)
+        next_observations = preprocess_obs(next_observations)
         
         # Initialize transition model states
-            self.transition_model.init_states(self.args.batch_size, device) # (N,128) 
+        self.transition_model.init_states(self.args.batch_size, device="cpu") # (N,128) 
         self.history = self.transition_model.prev_history # (N,128)
 
         # Train encoder
-            if step == 0:
+        step = 0
-                step += 1
+        total_steps = 10000
-            for _ in range(self.args.collection_interval // self.args.episode_length+1):
+        metrics = {}
-                counter += 1
+        while step < total_steps:
             for i in range(self.args.episode_length-1):
                 if i > 0:
                     # Encode observations and next_observations
@@ -347,11 +331,16 @@ class DPI:
                                                                           self.negative_current_states_dict,
                                                                           predicted_current_state_dict
                                                                           )
+                    #likeli_loss = torch.tensor(likeli_loss.numpy(),dtype=torch.float32, requires_grad=True)
+                    #ikeli_loss = likeli_loss.mean()
                     
                     # Calculate encoder loss
                     encoder_loss = self._past_encoder_loss(self.current_states_dict,
                                                         predicted_current_state_dict)
 
+                    #total_ub_loss += ub_loss
+                    #total_encoder_loss += encoder_loss
+                    
                     # contrastive projection
                     vec_anchor = predicted_current_state_dict["sample"]
                     vec_positive = self.next_states_dict["sample"].detach()
@@ -360,7 +349,7 @@ class DPI:
 
                     # contrastive loss
                     logits = self.contrastive_head(z_anchor, z_positive)
-                        labels = torch.arange(logits.shape[0]).long().to(device)
+                    labels = labels = torch.arange(logits.shape[0]).long()
                     lb_loss = F.cross_entropy(logits, labels)
                     
                     # behaviour learning
@@ -371,7 +360,7 @@ class DPI:
                                                                                 imagine_horizon)
                     
                     # decoder loss
-                        horizon = np.minimum(self.args.imagine_horizon, self.args.episode_length-1-i)
+                    horizon = np.minimum(50-i, imagine_horizon)
                     obs_dist = self.obs_decoder(imagined_rollout["sample"][:horizon])
                     decoder_loss = -torch.mean(obs_dist.log_prob(next_observations[i:i+horizon][:,:,:3,:,:]))
 
@@ -380,18 +369,12 @@ class DPI:
                     reward_loss = -torch.mean(reward_dist.log_prob(rewards[:-1]))        
 
                     # update models
-                        world_model_loss = encoder_loss + 100 * ub_loss + lb_loss + reward_loss + decoder_loss * 1e-2
+                    world_model_loss = encoder_loss + ub_loss + lb_loss + decoder_loss * 1e-2
                     self.world_model_opt.zero_grad()
                     world_model_loss.backward()
                     nn.utils.clip_grad_norm_(self.world_model_parameters, self.args.grad_clip_norm)
                     self.world_model_opt.step()
 
-                        # update momentum encoder
-                        soft_update_params(self.obs_encoder, self.obs_encoder_momentum, self.args.encoder_tau)
-
-                        # update momentum projection head
-                        soft_update_params(self.prjoection_head, self.prjoection_head_momentum, self.args.encoder_tau)
-
                     # actor loss
                     with FreezeParameters(self.world_model_modules + self.value_modules):
                         imag_rew_dist = self.reward_model(imagined_rollout["sample"])
@@ -436,62 +419,39 @@ class DPI:
                     if step % self.args.value_target_update_freq == 0:
                         self.target_value_model = copy.deepcopy(self.value_model)
                     
-                        # counter for reward
+                    # update momentum encoder
-                        count = np.arange((counter-1) * (self.args.batch_size), (counter) * (self.args.batch_size))
+                    soft_update_params(self.obs_encoder, self.obs_encoder_momentum, self.args.encoder_tau)
 
-                        
+                    # update momentum projection head
-                        if step % self.args.logging_freq:
+                    soft_update_params(self.prjoection_head, self.prjoection_head_momentum, self.args.encoder_tau)
-                            writer.add_scalar('World Loss/World Loss', world_model_loss.detach().item(), step)
-                            writer.add_scalar('Main Models Loss/Encoder Loss', encoder_loss.detach().item(), step)
-                            writer.add_scalar('Main Models Loss/Decoder Loss', decoder_loss, step)
-                            writer.add_scalar('Actor Critic Loss/Actor Loss', actor_loss.detach().item(), step)
-                            writer.add_scalar('Actor Critic Loss/Value Loss', value_loss.detach().item(), step)
-                            writer.add_scalar('Actor Critic Loss/Reward Loss', reward_loss.detach().item(), step)
-                            writer.add_scalar('Bound Loss/Upper Bound Loss', ub_loss.detach().item(), step)
-                            writer.add_scalar('Bound Loss/Lower Bound Loss', lb_loss.detach().item(), step)                            
 
                     step += 1
+                    
+                    if step % self.args.logging_freq:
+                        writer.add_scalar('Main Loss/World Loss', world_model_loss, step)
+                        writer.add_scalar('Main Models Loss/Encoder Loss', encoder_loss, step)
+                        writer.add_scalar('Main Models Loss/Decoder Loss', decoder_loss, step)
+                        writer.add_scalar('Actor Critic Loss/Actor Loss', actor_loss, step)
+                        writer.add_scalar('Actor Critic Loss/Value Loss', value_loss, step)
+                        writer.add_scalar('Actor Critic Loss/Reward Loss', reward_loss, step)
+                        writer.add_scalar('Bound Loss/Upper Bound Loss', ub_loss, step)
+                        writer.add_scalar('Bound Loss/Lower Bound Loss', lb_loss, step)
+                        
+                    """
+                    if step % self.args.logging_freq:
+                        metrics['Upper Bound Loss'] = ub_loss.item()
+                        metrics['Encoder Loss'] = encoder_loss.item()
+                        metrics['Decoder Loss'] = decoder_loss.item()
+                        metrics["Lower Bound Loss"] = lb_loss.item()
+                        metrics["World Model Loss"] = world_model_loss.item()
+                        wandb.log(metrics)
+                    """
+
                     if step>total_steps:
                         print("Training finished")
                         break
 
-                        # save model
-                        if step % self.args.saving_interval == 0:
-                            path =  os.path.dirname(os.path.realpath(__file__)) + "/saved_models/models.pth"
-                            self.save_models(path)
 
-                        #torch.cuda.empty_cache()    # memory leak issues
-                
-                for j in range(len(all_rews)):
-                                writer.add_scalar('Rewards/Rewards', all_rews[j], count[j])
-                
-
-    def evaluate(self, env, eval_episodes, render=False):
-
-        episode_rew = np.zeros((eval_episodes))
-
-        video_images = [[] for _ in range(eval_episodes)]
-
-        for i in range(eval_episodes):
-            obs = env.reset()
-            done = False
-            prev_state = self.rssm.init_state(1, self.device)
-            prev_action = torch.zeros(1, self.action_size).to(self.device)
-
-            while not done:
-                with torch.no_grad():
-                    posterior, action = self.act_with_world_model(obs, prev_state, prev_action)
-                action = action[0].cpu().numpy()
-                next_obs, rew, done, _ = env.step(action)
-                prev_state = posterior
-                prev_action = torch.tensor(action, dtype=torch.float32).to(self.device).unsqueeze(0)
-
-                episode_rew[i] += rew
-
-                if render:
-                    video_images[i].append(obs['image'].transpose(1,2,0).copy())
-                obs = next_obs
-        return episode_rew, np.array(video_images[:self.args.max_videos_to_save])
 
     def _upper_bound_minimization(self, last_states, current_states, negative_current_states, predicted_current_states):
         club_sample = CLUBSample(last_states,
@@ -509,6 +469,8 @@ class DPI:
         # predicted current state distribution
         predicted_curr_states_dist = predicted_curr_states_dict["distribution"]
 
+        
+
         # KL divergence loss
         loss = torch.distributions.kl.kl_divergence(curr_states_dist, predicted_curr_states_dist).mean()
 
@@ -540,26 +502,10 @@ class DPI:
         returns = torch.flip(torch.stack(rets), [0])
         return returns
 
-    def save_models(self, save_path):
-        torch.save(
-            {'rssm' : self.transition_model.state_dict(),
-            'actor': self.actor_model.state_dict(),
-            'reward_model': self.reward_model.state_dict(),
-            'obs_encoder': self.obs_encoder.state_dict(),
-            'obs_decoder': self.obs_decoder.state_dict(),
-            'actor_optimizer': self.actor_opt.state_dict(),
-            'value_optimizer': self.value_opt.state_dict(),
-            'world_model_optimizer': self.world_model_opt.state_dict(),}, save_path)
-
 if __name__ == '__main__':
     args = parse_args()
     
     writer = SummaryWriter()
 
-
+    dpi = DPI(args, writer)
-    device = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')
+    dpi.train()
-
-    step = 0
-    total_steps = 10000
-    dpi = DPI(args)
-    dpi.train(step,total_steps)

DPI/utils.py

@@ -1,3 +1,9 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
 import os
 import random
 import numpy as np
@@ -102,49 +108,6 @@ class FrameStack(gym.Wrapper):
         return np.concatenate(list(self._frames), axis=0)
 
 
-class ActionRepeat:
-    def __init__(self, env, amount):
-        self._env = env
-        self._amount = amount
-
-    def __getattr__(self, name):
-        return getattr(self._env, name)
-
-    def step(self, action):
-        done = False
-        total_reward = 0
-        current_step = 0
-        while current_step < self._amount and not done:
-            obs, reward, done, info = self._env.step(action)
-            total_reward += reward
-            current_step += 1
-        return obs, total_reward, done, info
-
-
-class NormalizeActions:
-    def __init__(self, env):
-        self._env = env
-        self._mask = np.logical_and(
-            np.isfinite(env.action_space.low),
-            np.isfinite(env.action_space.high))
-        self._low = np.where(self._mask, env.action_space.low, -1)
-        self._high = np.where(self._mask, env.action_space.high, 1)
-
-    def __getattr__(self, name):
-        return getattr(self._env, name)
-
-    @property
-    def action_space(self):
-        low = np.where(self._mask, -np.ones_like(self._low), self._low)
-        high = np.where(self._mask, np.ones_like(self._low), self._high)
-        return gym.spaces.Box(low, high, dtype=np.float32)
-
-    def step(self, action):
-        original = (action + 1) / 2 * (self._high - self._low) + self._low
-        original = np.where(self._mask, original, action)
-        return self._env.step(original)
-
-
 class ReplayBuffer:
     def __init__(self, size, obs_shape, action_size, seq_len, batch_size, args):
         self.size = size
@@ -201,11 +164,11 @@ class ReplayBuffer:
         non_zero_indices = np.nonzero(buffer.episode_count)[0]
         variable = variable[non_zero_indices]
         if obs:
-            variable = variable.reshape(-1, self.args.episode_length,
+            variable = variable.reshape(self.args.batch_size, self.args.episode_length,
                                         self.args.frame_stack*self.args.channels,
                                         self.args.image_size,self.args.image_size).transpose(1, 0, 2, 3, 4)
         else:
-            variable = variable.reshape(variable.shape[0]//self.args.episode_length, self.args.episode_length, -1).transpose(1, 0, 2)
+            variable = variable.reshape(self.args.batch_size, self.args.episode_length, -1).transpose(1, 0, 2)
         return variable
 
     def transform_grouped_steps(self, variable):
@@ -214,16 +177,6 @@ class ReplayBuffer:
                                     self.args.image_size,self.args.image_size)
         return variable
     
-    def sample_random_idx(self, buffer_length):
-        random_indices = random.sample(range(0, buffer_length), self.args.batch_size) 
-        return random_indices
-
-    def group_and_sample_random_batch(self, buffer, variable_name, device, random_indices, is_obs=True, offset=0):
-        if offset == 0:
-            variable_tensor = torch.tensor(self.group_steps(buffer,variable_name, is_obs)).float()[:self.args.episode_length-1].to(device)
-        else:
-            variable_tensor = torch.tensor(self.group_steps(buffer,variable_name, is_obs)).float()[offset:].to(device)
-        return variable_tensor[:,random_indices,:,:,:] if is_obs else variable_tensor[:,random_indices,:]
 
 def make_env(args):
     # For making ground plane transparent, change rgba to (0, 0, 0, 0) in local_dm_control_suite/{domain_name}.xml,