MetaGPT/expo/MCTS.py
2024-09-09 14:52:25 +08:00

372 lines
14 KiB
Python

import math
import os
import pickle
import random
import numpy as np
import pandas as pd
from expo.data.dataset import generate_task_requirement, get_split_dataset_path
from expo.evaluation.evaluation import evaluate_score
from expo.insights.instruction_generator import InstructionGenerator
from expo.research_assistant import ResearchAssistant
from expo.utils import get_exp_pool_path, load_execute_notebook, mcts_logger
from metagpt.tools.tool_recommend import ToolRecommender
from metagpt.utils.common import read_json_file
def initialize_di_root_node(task, data_config, low_is_better=False, reflection=True, name=""):
start_task_id = 2
state = create_initial_state(
task, start_task_id=start_task_id, data_config=data_config, low_is_better=low_is_better, name=name
)
role = ResearchAssistant(
node_id="0", start_task_id=start_task_id, use_reflection=reflection, role_dir=state["node_dir"]
)
return role, Node(parent=None, state=state, action=None, value=0)
def create_initial_state(task, start_task_id, data_config, low_is_better, name):
initial_state = {
"task": task,
"work_dir": data_config["work_dir"],
"node_dir": os.path.join(data_config["work_dir"], data_config["role_dir"], f"{task}{name}"),
"dataset_config": data_config["datasets"][task],
"datasets_dir": get_split_dataset_path(task, data_config),
"exp_pool_path": get_exp_pool_path(task, data_config, pool_name="ds_analysis_pool"),
"requirement": generate_task_requirement(task, data_config),
"has_run": False,
"start_task_id": start_task_id,
"low_is_better": low_is_better,
}
return initial_state
class Node:
state: dict = {}
action: str = None
value: float = 0
visited: int = 0
children: list = []
normalized_reward: dict = {"train_score": 0, "dev_score": 0, "test_score": 0}
parent = None
def __init__(self, parent=None, state=None, action=None, value=0, max_depth=4, **kwargs):
self.state = state
self.action = action
self.value = value
self.raw_value = 0
self.raw_reward = dict()
self.parent = parent
self.children = []
self.max_depth = max_depth
self.depth = self.generate_depth()
self.id = self.generate_id()
if self.parent is not None:
self.save_node()
def avg_value(self):
if self.visited == 0:
return 0
return self.value / self.visited
def __hash__(self):
return hash(self.id)
def save_node(self):
os.makedirs(self.state["node_dir"], exist_ok=True)
with open(os.path.join(self.state["node_dir"], f"Node-{self.id}.pkl"), "wb") as f:
pickle.dump(self, f)
def load_node(self):
with open(os.path.join(self.state["node_dir"], f"Node-{self.id}.pkl"), "rb") as f:
return pickle.load(f)
def get_depth(self):
return self.depth
def generate_depth(self):
if self.parent is None:
return 0
else:
return self.parent.depth + 1
def generate_id(self):
if self.parent is None:
return "0"
else:
num_sibling = len(self.parent.children)
return f"{self.parent.id}-{num_sibling}"
def is_terminal(self):
return int(self.state["start_task_id"]) == self.max_depth + 1
def is_fully_expanded(self):
return len(self.children) > 0
def add_child(self, child_node):
self.children.append(child_node)
def update(self, reward: dict, child_node=None):
if child_node is not None:
child_role = child_node.load_role()
role = self.load_role()
role.update_til_start_task(child_role)
role.save_state()
else:
self.raw_value = reward["test_score"]
self.value += reward["score"]
self.visited += 1
self.save_node()
def get_role_path(self):
fname = f"Node-{self.id}.json"
role_path = os.path.join(self.state["node_dir"], fname)
return role_path
def load_role(self):
role_dict = read_json_file(self.get_role_path())
if role_dict.get("tool_recommender") is None:
role_dict["tool_recommender"] = ToolRecommender()
elif isinstance(role_dict.get("tool_recommender", {}).get("tools"), dict):
role_dict["tool_recommender"]["tools"] = list(role_dict["tool_recommender"]["tools"].keys())
role = ResearchAssistant(**role_dict)
if self.parent is not None: # TODO: Check this
parent_role = self.parent.load_role()
role.update_til_start_task(parent_role, backward=False)
role.remap_tasks()
return role
def save_new_role(self, role: ResearchAssistant):
role.node_id = self.id
role.start_task_id = self.state["start_task_id"]
role.state_saved = False
role.change_next_instruction(self.action)
mcts_logger.log("MCTS", f"Saving new role: {role.node_id}")
role = role.model_copy()
role.save_state(static_save=True)
async def expand(self, max_children):
if self.is_fully_expanded():
return
insight_geneartor = InstructionGenerator()
role = self.load_role()
original_instruction = role.get_next_instruction()
insights = await insight_geneartor.generate_new_instructions(
task_id=role.start_task_id + 1,
original_instruction=original_instruction,
max_num=max_children,
file_path=self.state["exp_pool_path"],
)
new_state = self.state.copy()
new_state["start_task_id"] += 1
for insight in insights:
new_role = role.model_copy()
node = Node(parent=self, state=new_state, action=insight, value=0)
node.save_new_role(new_role)
self.add_child(node)
def evaluate_prediction(self, split):
pred_path = os.path.join(self.state["work_dir"], self.state["task"], f"{split}_predictions.csv")
pred_node_path = os.path.join(self.state["node_dir"], f"Node-{self.id}-{split}_predictions.csv")
gt_path = os.path.join(self.state["datasets_dir"][f"{split}_target"])
preds = pd.read_csv(pred_path)["target"]
preds.to_csv(pred_node_path, index=False)
gt = pd.read_csv(gt_path)["target"]
metric = self.state["dataset_config"]["metric"]
# remove original predictions.csv
os.remove(pred_path)
return evaluate_score(preds, gt, metric)
def evaluate_simulation(self, score_dict):
scores = {"dev_score": self.evaluate_prediction("dev"), "test_score": self.evaluate_prediction("test")}
scores["score"] = scores["dev_score"]
score_dict.update(scores)
return score_dict
async def run_node(self, role=None):
if self.is_terminal() and role is not None:
if role.state_saved:
return self.raw_reward
max_retries = 3
num_runs = 1
run_finished = False
while num_runs <= max_retries and not run_finished:
try:
if not role:
role = self.load_role()
await load_execute_notebook(role) # execute previous notebook's code
await role.run(with_message="continue")
else:
await role.run(with_message=self.state["requirement"])
score_dict = await role.get_score()
score_dict = self.evaluate_simulation(score_dict)
self.raw_reward = score_dict
run_finished = True
except Exception as e:
mcts_logger.log("MCTS", f"Error in running the role: {e}")
num_runs += 1
if not run_finished:
mcts_logger.log("MCTS", f"Role {role.node_id} failed to run")
if self.state["low_is_better"]:
score_dict = {"test_score": np.inf, "dev_score": np.inf, "score": np.inf}
else:
score_dict = {"test_score": 0, "dev_score": 0, "score": 0}
self.raw_reward = score_dict
if self.state["low_is_better"]:
# normalized the score to be between 0 and 1, and higher is better
def normalize_score(score):
if score == -1:
return 0
return 1 / (1 + score)
score_dict = {k: normalize_score(v) for k, v in score_dict.items()}
self.normalized_reward = score_dict
return score_dict
class MCTS:
# data_path
root_node: Node = None
children: dict = {}
max_depth: int = 5
c_explore: float = 1.4
c_unvisited: float = 0.8
def __init__(self, root_node, max_depth):
self.root_node = root_node
self.max_depth = max_depth
def select(self, node: Node):
node = self.best_child()
mcts_logger.log("MCTS", f"Selected node id: {node.id}")
return node
def best_child(self):
def uct(node: Node):
n_visits = node.visited if node.visited else self.c_unvisited
avg_value = node.avg_value() if node.visited else node.value / self.c_unvisited
return avg_value + self.c_explore * math.sqrt(math.log(node.parent.visited) / n_visits)
if len(self.children) == 0:
return self.root_node
all_children = [child for children in self.children.values() for child in children]
return max(all_children, key=uct)
async def expand(self, node: Node, max_children=5):
await node.expand(max_children)
if node not in self.children or not self.children[node]:
self.children[node] = node.children
return node.children
async def simulate(self, node: Node, role=None):
"Returns the reward for a random simulation (to completion) of `node`"
mcts_logger.log("MCTS", f"Start simulating node {node.id}:")
while node.children:
node = random.choice(node.children)
reward = await node.run_node(role)
mcts_logger.log("MCTS", f"Simulated node's reward: {reward}")
return reward
def backpropagate(self, node: Node, reward):
child_node = node
node.update(reward)
node = node.parent
while node is not None:
node.update(reward, child_node)
node, child_node = node.parent, node
def best_path(self, root: Node):
best_child = root
global_best_score = root.normalized_reward["test_score"]
dev_best_score = root.normalized_reward["dev_score"]
def bfs(node: Node, best_score, best_child: Node, split):
assert split in ["test_score", "dev_score"]
if node not in self.children:
return best_score, best_child
for child in self.children[node]:
score = child.normalized_reward[split]
print(child.id, split, score)
if score > best_score:
best_score = score
best_child = child
best_score, best_child = bfs(child, best_score, best_child, split)
return best_score, best_child
_, global_best_child = bfs(root, global_best_score, best_child, "test_score")
_, dev_best_child = bfs(root, dev_best_score, best_child, "dev_score")
return {"dev_best": dev_best_child, "global_best": global_best_child}
def get_num_simulations(self):
return self.root_node.visited
async def search(self, task, data_config, name, rollouts, load_tree=False, low_is_better=False, reflection=False):
role, root = initialize_di_root_node(
task, data_config, low_is_better=low_is_better, reflection=reflection, name=name
)
self.root_node = root
tree_loaded = False
if load_tree:
tree_loaded = self.load_tree()
mcts_logger.log("MCTS", f"Number of simulations: {self.get_num_simulations()}")
mcts_logger.log("MCTS", f"Tree loaded: {tree_loaded}")
if not tree_loaded:
rollouts -= 2 # 2 rollouts for the initial tree
if rollouts < 0:
raise ValueError("Rollouts must be greater than 2 if there is no tree to load")
self.children[root] = []
reward = await self.simulate(root, role)
self.backpropagate(root, reward)
node, reward = await self.expand_and_simulate(root)
# self.backpropagate(node, reward)
else:
root = self.root_node
for _ in range(rollouts): # number of rollouts
mcts_logger.log("MCTS", f"Start the next rollout {_+1}")
node = self.select(root)
if node.is_terminal():
if node.raw_value == 0:
reward = await self.simulate(node)
else:
reward = {"test_score": node.raw_value, "score": node.raw_reward["score"]}
mcts_logger.log("MCTS", f"Terminal node's reward: {reward}")
self.backpropagate(node, reward)
else:
node, reward = await self.expand_and_simulate(node)
# self.backpropagate(node, reward)
return self.best_path(root)
async def expand_and_simulate(self, node):
# Expand and randomly select a child node, then simulate it
if node.visited > 0:
children = await self.expand(node)
node = random.choice(children)
reward = await self.simulate(node)
self.backpropagate(node, reward)
return node, reward
def load_tree(self):
def load_children_node(node):
mcts_logger.log("MCTS", f"Load node {node.id}'s child: {node.children}")
if node.is_terminal() or not node.children:
return
for child in node.children:
child.load_node()
self.children[child] = child.children
load_children_node(child)
# Load all pkl files in the node_dir
all_pkl_files = os.listdir(self.root_node.state["node_dir"])
all_pkl_files = [f for f in all_pkl_files if f.endswith(".pkl")]
if os.path.exists(os.path.join(self.root_node.state["node_dir"], "Node-0.pkl")):
with open(os.path.join(self.root_node.state["node_dir"], "Node-0.pkl"), "rb") as f:
self.root_node = pickle.load(f)
self.children[self.root_node] = self.root_node.children
load_children_node(self.root_node)
if self.children:
return True
return False