Move classes from IMCTS and BayesianMCTS in seperate files

This commit is contained in:
2024-01-30 17:48:44 +01:00
parent 3f18d0a0d5
commit b6bb61ec45
4 changed files with 210 additions and 191 deletions

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@@ -1,139 +1,10 @@
import math import chess
import torch.distributions as dist import torch.distributions as dist
from chesspp.mcts.i_mcts import *
from chesspp.i_strategy import IStrategy from chesspp.i_strategy import IStrategy
from chesspp.util_gaussian import gaussian_ucb1, max_gaussian, min_gaussian from chesspp.mcts.baysian_mcts_node import BayesianMctsNode
from chesspp.mcts.i_mcts import IMcts
from chesspp.mcts.i_mcts_node import IMctsNode
class BayesianMctsNode(IMctsNode):
def __init__(self, board: chess.Board, strategy: IStrategy, color: chess.Color, parent: Self | None,
move: chess.Move | None,
random_state: random.Random, inherit_result: int | None = None, depth: int = 0, visits: int = 0):
super().__init__(board, strategy, parent, move, random_state)
self.color = color # Color of the player whose turn it is
self.visits = visits
self.result = inherit_result if inherit_result is not None else 0
self._set_mu_sigma()
self.depth = depth
def _create_child(self, move: chess.Move) -> IMctsNode:
copied_board = self.board.copy()
copied_board.push(move)
return BayesianMctsNode(copied_board, self.strategy, not self.color, self, move, self.random_state, self.result,
self.depth + 1)
def _set_mu_sigma(self) -> None:
self.mu = self.result
self.sigma = 1
def _is_new_ucb1_better(self, current, new) -> bool:
if self.color == chess.WHITE:
# maximize ucb1
return new > current
else:
# minimize ubc1
return new < current
def _select_best_child(self) -> IMctsNode:
"""
Returns the child with the *best* ucb1 score.
It chooses the child with maximum ucb1 for WHITE, and with minimum ucb1 for BLACK.
"""
if self.board.is_game_over():
return self
best_child = self.random_state.choice(self.children)
best_ucb1 = gaussian_ucb1(best_child.mu, best_child.sigma, self.visits)
for child in self.children:
# if child has no visits, prioritize this child.
if child.visits == 0:
best_child = child
break
# save child if it has a *better* score, than our previous best child.
ucb1 = gaussian_ucb1(child.mu, child.sigma, self.visits)
if self._is_new_ucb1_better(best_ucb1, ucb1):
best_ucb1 = ucb1
best_child = child
return best_child
def update_depth(self, depth: int) -> None:
self.depth = depth
for c in self.children:
c.update_depth(depth + 1)
def select(self) -> IMctsNode:
if len(self.children) == 0 or self.board.is_game_over():
return self
return self._select_best_child().select()
def expand(self) -> IMctsNode:
if self.visits == 0:
return self
for move in self.legal_moves:
self.children.append(self._create_child(move))
return self._select_best_child()
def rollout(self, rollout_depth: int = 4) -> int:
copied_board = self.board.copy()
steps = self.depth
for i in range(rollout_depth):
if copied_board.is_game_over():
break
m = self.strategy.pick_next_move(copied_board)
if m is None:
break
copied_board.push(m)
steps += 1
steps = max(1, steps)
score = int(self.strategy.analyze_board(copied_board) / (math.log2(steps) + 1))
self.result = score
return score
def _combine_gaussians(self, mu1: float, sigma1: float, mu2: float, sigma2: float) -> tuple[float, float]:
if self.color == chess.WHITE:
return max_gaussian(mu1, sigma1, mu2, sigma2)
else:
return min_gaussian(mu1, sigma1, mu2, sigma2)
def backpropagate(self, score: int | None = None) -> None:
self.visits += 1
if score is not None:
self.result = score
if len(self.children) == 0:
# leaf node
self._set_mu_sigma()
else:
# interior node
shuffled_children = self.random_state.sample(self.children, len(self.children))
mu = shuffled_children[0].mu
sigma = shuffled_children[0].sigma
for c in shuffled_children[1:]:
mu, sigma = self._combine_gaussians(mu, sigma, c.mu, c.sigma)
# if max_sigma == 0:
# max_sigma = 0.001
self.mu = mu
self.sigma = sigma
if self.parent:
self.parent.backpropagate()
def print(self, indent=0):
print("\t" * indent + f"move={self.move}, visits={self.visits}, mu={self.mu}, sigma={self.sigma}")
for c in self.children:
c.print(indent + 1)
class BayesianMcts(IMcts): class BayesianMcts(IMcts):
@@ -172,7 +43,7 @@ class BayesianMcts(IMcts):
def get_children(self) -> list[IMctsNode]: def get_children(self) -> list[IMctsNode]:
return self.root.children return self.root.children
def get_moves(self) -> Dict[chess.Move, dist.Normal]: def get_moves(self) -> dict[chess.Move, dist.Normal]:
res = {} res = {}
for c in self.root.children: for c in self.root.children:
res[c.move] = dist.Normal(c.mu, c.sigma) res[c.move] = dist.Normal(c.mu, c.sigma)

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@@ -0,0 +1,139 @@
import math
import random
from typing import Self
import chess
from chesspp.i_strategy import IStrategy
from chesspp.mcts.i_mcts_node import IMctsNode
from chesspp.util_gaussian import gaussian_ucb1, max_gaussian, min_gaussian
class BayesianMctsNode(IMctsNode):
def __init__(self, board: chess.Board, strategy: IStrategy, color: chess.Color, parent: Self | None,
move: chess.Move | None,
random_state: random.Random, inherit_result: int | None = None, depth: int = 0, visits: int = 0):
super().__init__(board, strategy, parent, move, random_state)
self.color = color # Color of the player whose turn it is
self.visits = visits
self.result = inherit_result if inherit_result is not None else 0
self._set_mu_sigma()
self.depth = depth
def _create_child(self, move: chess.Move) -> IMctsNode:
copied_board = self.board.copy()
copied_board.push(move)
return BayesianMctsNode(copied_board, self.strategy, not self.color, self, move, self.random_state, self.result,
self.depth + 1)
def _set_mu_sigma(self) -> None:
self.mu = self.result
self.sigma = 1
def _is_new_ucb1_better(self, current, new) -> bool:
if self.color == chess.WHITE:
# maximize ucb1
return new > current
else:
# minimize ubc1
return new < current
def _select_best_child(self) -> IMctsNode:
"""
Returns the child with the *best* ucb1 score.
It chooses the child with maximum ucb1 for WHITE, and with minimum ucb1 for BLACK.
"""
if self.board.is_game_over():
return self
best_child = self.random_state.choice(self.children)
best_ucb1 = gaussian_ucb1(best_child.mu, best_child.sigma, self.visits)
for child in self.children:
# if child has no visits, prioritize this child.
if child.visits == 0:
best_child = child
break
# save child if it has a *better* score, than our previous best child.
ucb1 = gaussian_ucb1(child.mu, child.sigma, self.visits)
if self._is_new_ucb1_better(best_ucb1, ucb1):
best_ucb1 = ucb1
best_child = child
return best_child
def update_depth(self, depth: int) -> None:
self.depth = depth
for c in self.children:
c.update_depth(depth + 1)
def select(self) -> IMctsNode:
if len(self.children) == 0 or self.board.is_game_over():
return self
return self._select_best_child().select()
def expand(self) -> IMctsNode:
if self.visits == 0:
return self
for move in self.legal_moves:
self.children.append(self._create_child(move))
return self._select_best_child()
def rollout(self, rollout_depth: int = 4) -> int:
copied_board = self.board.copy()
steps = self.depth
for i in range(rollout_depth):
if copied_board.is_game_over():
break
m = self.strategy.pick_next_move(copied_board)
if m is None:
break
copied_board.push(m)
steps += 1
steps = max(1, steps)
score = int(self.strategy.analyze_board(copied_board) / (math.log2(steps) + 1))
self.result = score
return score
def _combine_gaussians(self, mu1: float, sigma1: float, mu2: float, sigma2: float) -> tuple[float, float]:
if self.color == chess.WHITE:
return max_gaussian(mu1, sigma1, mu2, sigma2)
else:
return min_gaussian(mu1, sigma1, mu2, sigma2)
def backpropagate(self, score: int | None = None) -> None:
self.visits += 1
if score is not None:
self.result = score
if len(self.children) == 0:
# leaf node
self._set_mu_sigma()
else:
# interior node
shuffled_children = self.random_state.sample(self.children, len(self.children))
mu = shuffled_children[0].mu
sigma = shuffled_children[0].sigma
for c in shuffled_children[1:]:
mu, sigma = self._combine_gaussians(mu, sigma, c.mu, c.sigma)
# if max_sigma == 0:
# max_sigma = 0.001
self.mu = mu
self.sigma = sigma
if self.parent:
self.parent.backpropagate()
def print(self, indent=0):
print("\t" * indent + f"move={self.move}, visits={self.visits}, mu={self.mu}, sigma={self.sigma}")
for c in self.children:
c.print(indent + 1)

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@@ -1,62 +1,11 @@
import chess
import random import random
from abc import ABC, abstractmethod from abc import ABC, abstractmethod
from typing import Dict, Self from typing import Dict
import chess
from chesspp.i_strategy import IStrategy from chesspp.i_strategy import IStrategy
from chesspp.mcts.i_mcts_node import IMctsNode
class IMctsNode(ABC):
def __init__(self, board: chess.Board, strategy: IStrategy, parent: Self | None, move: chess.Move | None,
random_state: random.Random):
self.board = board
self.strategy = strategy
self.parent = parent
self.children = []
self.move = move
self.legal_moves = list(board.legal_moves)
self.random_state = random_state
self.depth = 0
@abstractmethod
def select(self) -> Self:
"""
Selects the next node leaf node in the tree
:return:
"""
pass
@abstractmethod
def expand(self) -> Self:
"""
Expands this node creating X child leaf nodes, i.e., choose an action and apply it to the board
:return:
"""
pass
@abstractmethod
def rollout(self, rollout_depth: int = 20) -> int:
"""
Rolls out the node by simulating a game for a given depth.
Sometimes this step is called 'simulation' or 'playout'.
:return: the score of the rolled out game
"""
pass
@abstractmethod
def backpropagate(self, score: float) -> None:
"""
Backpropagates the results of the rollout
:param score:
:return:
"""
pass
def update_depth(self, depth: int) -> None:
"""
Recursively updates the depth the current node and all it's children
:param depth: new depth for current node
:return:
"""
class IMcts(ABC): class IMcts(ABC):

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@@ -0,0 +1,60 @@
import random
from abc import ABC, abstractmethod
from typing import Self
import chess
from chesspp.i_strategy import IStrategy
class IMctsNode(ABC):
def __init__(self, board: chess.Board, strategy: IStrategy, parent: Self | None, move: chess.Move | None,
random_state: random.Random):
self.board = board
self.strategy = strategy
self.parent = parent
self.children = []
self.move = move
self.legal_moves = list(board.legal_moves)
self.random_state = random_state
self.depth = 0
@abstractmethod
def select(self) -> Self:
"""
Selects the next node leaf node in the tree
:return:
"""
pass
@abstractmethod
def expand(self) -> Self:
"""
Expands this node creating X child leaf nodes, i.e., choose an action and apply it to the board
:return:
"""
pass
@abstractmethod
def rollout(self, rollout_depth: int = 20) -> int:
"""
Rolls out the node by simulating a game for a given depth.
Sometimes this step is called 'simulation' or 'playout'.
:return: the score of the rolled out game
"""
pass
@abstractmethod
def backpropagate(self, score: float | None = None) -> None:
"""
Backpropagates the results of the rollout
:param score:
:return:
"""
pass
def update_depth(self, depth: int) -> None:
"""
Recursively updates the depth the current node and all it's children
:param depth: new depth for current node
:return:
"""