Files
katrain-qt/ai.py
T
2020-04-30 21:22:27 +02:00

158 lines
10 KiB
Python

import heapq
import math
import random
import time
from typing import Any, Dict, List, Tuple
import numpy as np
from common import OUTPUT_DEBUG, OUTPUT_ERROR, OUTPUT_INFO, var_to_grid
from engine import EngineDiedException
from game import Game, GameNode, IllegalMoveException, Move
def weighted_selection_without_replacement(items: List[Tuple[float, float, int, int]], pick_n: int) -> List[Tuple[float, float, int, int]]:
"""For a list of tuples where the second element is a weight, returns random items with those weights, without replacement."""
elt = [(math.log(random.random()) / item[1], item) for item in items] # magic
return [e[1] for e in heapq.nlargest(pick_n, elt)] # NB fine if too small
def dirichlet_noise(num, dir_alpha=0.3):
return np.random.dirichlet([dir_alpha] * num)
def fmt_moves(moves: List[Tuple[float, Move]]):
return ", ".join(f"{mv.gtp()} ({p:.2%})" for p, mv in moves)
def ai_move(game: Game, ai_mode: str, ai_settings: Dict) -> Tuple[Move, GameNode]:
cn = game.current_node
while not cn.analysis_ready:
time.sleep(0.01)
engine = game.engines[cn.next_player]
if engine.katago_process.poll() is not None: # TODO: clean up
raise EngineDiedException(f"Engine for {cn.next_player} ({engine.config}) died")
ai_mode = ai_mode.lower()
ai_thoughts = ""
candidate_ai_moves = cn.candidate_moves
if ("policy" in ai_mode or "p:" in ai_mode) and cn.policy:
policy_moves = cn.policy_ranking
pass_policy = cn.policy[-1]
top_5_pass = any([polmove[1].is_pass for polmove in policy_moves[:5]]) # dont make it jump around for the last few sensible non pass moves
size = game.board_size
policy_grid = var_to_grid(cn.policy, size) # type: List[List[float]]
top_policy_move = policy_moves[0][1]
ai_thoughts += f"Using policy based strategy, base top 5 moves are {fmt_moves(policy_moves[:5])}. "
if "policy" in ai_mode and cn.depth <= int(ai_settings["opening_moves"] * (game.board_size[0] * game.board_size[1])):
ai_mode = "p:weighted"
ai_thoughts += f"Switching to weighted strategy in the opening {int(ai_settings['opening_moves'] * (game.board_size[0]*game.board_size[1]))} moves."
ai_settings = {"pick_override": 0.9, "weaken_fac": 1, "lower_bound": 0.02}
if top_5_pass:
aimove = top_policy_move
ai_thoughts += "Playing top one because one of them is pass."
elif "policy" in ai_mode:
aimove = top_policy_move
ai_thoughts += f"Playing top policy move {aimove.gtp()}."
elif policy_moves[0][0] > ai_settings["pick_override"]:
aimove = top_policy_move
ai_thoughts += f"Top policy move has weight > {ai_settings['pick_override']:.1%}, so overriding other strategies."
elif "weighted" in ai_mode:
lower_bound = max(0, ai_settings["lower_bound"])
weaken_fac = max(0.01, ai_settings["weaken_fac"])
weighted_coords = [(policy_grid[y][x], policy_grid[y][x] ** (1 / weaken_fac), x, y) for x in range(size[0]) for y in range(size[1]) if policy_grid[y][x] > lower_bound]
top = weighted_selection_without_replacement(weighted_coords, 1)
if top:
best = top[0]
policy_value = best[0]
coords = best[2:]
else:
policy_value = pass_policy
coords = None
aimove = Move(coords, player=cn.next_player) # just take a random move by policy w/o noise
ai_thoughts += f"Playing policy-weighted random move {aimove.gtp()} ({policy_value:.1%})" + (
" because no other moves were found." if not top else f" because strategy is weighted (lower bound={lower_bound:.2%}, num moves > lb={len(weighted_coords)})."
)
elif "noise" in ai_mode:
noise_str = ai_settings["noise_strength"]
lower_bound = max(0, ai_settings["lower_bound"])
selected_policy_moves = [(pol, mv) for pol, mv in policy_moves if not mv.is_pass if pol > lower_bound]
d_noise = dirichlet_noise(len(selected_policy_moves))
noisy_policy_moves = [(((1 - noise_str) * pol + noise_str * noise), mv) for ((pol, mv), noise) in zip(selected_policy_moves, d_noise)]
new_top = heapq.nlargest(5, noisy_policy_moves)
aimove = new_top[0][1]
ai_thoughts += f"Noisy policy strategy (strength={noise_str:.2f}) generated 5 moves {fmt_moves(new_top)} so picked {aimove.gtp()} ({policy_grid[aimove.coords[1]][aimove.coords[0]]:.2%}). "
elif "p:" in ai_mode:
legal_policy_moves = [(pol, mv) for pol, mv in policy_moves if not mv.is_pass if pol > 0]
n_moves = int(ai_settings["pick_frac"] * len(legal_policy_moves) + ai_settings["pick_n"])
if "influence" in ai_mode or "territory" in ai_mode:
thr_line = ai_settings["threshold"] - 1 # zero-based
if "influence" in ai_mode:
weight = lambda x, y: (1 / ai_settings["line_weight"]) ** (max(0, thr_line - min(size[0] - 1 - x, x)) + max(0, thr_line - min(size[1] - 1 - y, y)))
else:
weight = lambda x, y: (1 / ai_settings["line_weight"]) ** (max(0, min(size[0] - 1 - x, x, size[1] - 1 - y, y) - thr_line))
weighted_coords = [(policy_grid[y][x] * weight(x, y), weight(x, y), x, y) for x in range(size[0]) for y in range(size[1]) if policy_grid[y][x] > 0]
ai_thoughts += f"Generated weights for {ai_mode} according to weight factor {ai_settings['line_weight']} and distance from {thr_line+1}th line. "
elif "local" in ai_mode or "tenuki" in ai_mode:
var = ai_settings["stddev"] ** 2
if not cn.single_move or cn.single_move.coords is None:
weighted_coords = [(1, 1, *top_policy_move.coords)] # if "pick" in ai_mode -> even
ai_thoughts += f"No previous non-pass move, faking weights to play top policy move. "
else:
mx, my = cn.single_move.coords
weighted_coords = [
(policy_grid[y][x], math.exp(-0.5 * ((x - mx) ** 2 + (y - my) ** 2) / var), x, y) for x in range(size[0]) for y in range(size[1]) if policy_grid[y][x] > 0
]
if "tenuki" in ai_mode:
weighted_coords = [(p, 1 - w, x, y) for p, w, x, y in weighted_coords]
ai_thoughts += f"Generated weights based on one minus gaussian with variance {var} around coordinates {mx},{my}. "
else:
ai_thoughts += f"Generated weights based on gaussian with variance {var} around coordinates {mx},{my}. "
elif "pick" in ai_mode:
weighted_coords = [(policy_grid[y][x], 1, x, y) for x in range(size[0]) for y in range(size[1]) if policy_grid[y][x] > 0]
else:
raise ValueError(f"Unknown AI mode {ai_mode}")
pick_moves = weighted_selection_without_replacement(weighted_coords, n_moves)
ai_thoughts += f"Picked {min(n_moves,len(weighted_coords))} random moves according to weights. "
if pick_moves:
new_top = [(p, Move((x, y), player=cn.next_player)) for p, wt, x, y in heapq.nlargest(5, pick_moves)]
aimove = new_top[0][1]
ai_thoughts += f"Top 5 among these were {fmt_moves(new_top)} and picked top {aimove.gtp()}. "
if new_top[0][0] < pass_policy:
ai_thoughts += f"But found pass ({pass_policy:.2%} to be higher rated than {aimove.gtp()} ({new_top[0][0]:.2%}) so will play top policy move instead."
aimove = top_policy_move
else:
aimove = top_policy_move
ai_thoughts += f"Pick policy strategy {ai_mode} failed to find legal moves, so is playing top policy move {aimove.gtp()}."
else:
raise ValueError(f"Unknown AI mode {ai_mode}")
elif "balance" in ai_mode and candidate_ai_moves[0]["move"] != "pass": # don't play suicidal to balance score - pass when it's best
sign = cn.player_sign(cn.next_player) # TODO check
sel_moves = [ # top move, or anything not too bad, or anything that makes you still ahead
move
for i, move in enumerate(candidate_ai_moves)
if i == 0
or move["visits"] >= ai_settings["min_visits"]
and (move["pointsLost"] < ai_settings["random_loss"] or move["pointsLost"] < ai_settings["max_loss"] and sign * move["scoreLead"] > ai_settings["target_score"])
]
aimove = Move.from_gtp(random.choice(sel_moves)["move"], player=cn.next_player) # TODO: could be weighted towards worse
ai_thoughts += f"Balance strategy selected moves {sel_moves} based on target score and max points lost, and randomly chose {aimove.gtp()}."
elif "jigo" in ai_mode and candidate_ai_moves[0]["move"] != "pass":
sign = cn.player_sign(cn.next_player) # TODO check
jigo_move = min(candidate_ai_moves, key=lambda move: abs(sign * move["scoreLead"] - ai_settings["target_score"]))
aimove = Move.from_gtp(jigo_move["move"], player=cn.next_player)
ai_thoughts += f"Jigo strategy found candidate moves {candidate_ai_moves} moves and chose {aimove.gtp()} as closest to 0.5 point win"
else:
if "default" not in ai_mode and "katago" not in ai_mode:
game.katrain.log(f"Unknown AI mode {ai_mode} or policy missing, using default.", OUTPUT_INFO)
ai_thoughts += f"Strategy {ai_mode} not found or unexpected fallback."
aimove = Move.from_gtp(candidate_ai_moves[0]["move"], player=cn.next_player)
ai_thoughts += f"Default strategy found {len(candidate_ai_moves)} moves returned from the engine and chose {aimove.gtp()} as top move"
game.katrain.log(f"AI thoughts: {ai_thoughts}", OUTPUT_DEBUG)
try:
played_node = game.play(aimove)
played_node.ai_thoughts = ai_thoughts
return aimove, played_node
except IllegalMoveException as e:
game.katrain.log(f"AI Strategy {ai_mode} generated illegal move {aimove.gtp()}: {e}", OUTPUT_ERROR)