add Bayesian and BOHB optimizers for global parameter search

This commit is contained in:
sam 2025-10-15 21:30:49 +08:00
parent f6c11867d2
commit 63c1ffcfe7
4 changed files with 377 additions and 110 deletions

View File

@ -1,10 +1,13 @@
"""Optimization utilities for DecisionEnv-based parameter tuning."""
from __future__ import annotations
import math
import random
from dataclasses import dataclass, field
from typing import Any, Dict, Iterable, List, Mapping, Sequence, Tuple
import numpy as np
from app.backtest.decision_env import DecisionEnv, EpisodeMetrics
from app.backtest.decision_env import ParameterSpec
from app.utils.logging import get_logger
@ -16,13 +19,18 @@ LOG_EXTRA = {"stage": "decision_bandit"}
@dataclass
class BanditConfig:
"""Configuration for epsilon-greedy bandit optimization."""
"""Configuration shared by all global parameter search strategies."""
experiment_id: str
strategy: str = "epsilon_greedy"
episodes: int = 20
epsilon: float = 0.2
seed: int | None = None
exploration_weight: float = 0.01
candidate_pool: int = 128
initial_candidates: int = 27
eta: int = 3
max_rounds: int = 3
@dataclass
@ -53,41 +61,40 @@ class BanditSummary:
return sum(item.reward for item in self.episodes) / len(self.episodes)
class EpsilonGreedyBandit:
"""Simple epsilon-greedy tuner using DecisionEnv as the reward oracle."""
class _BaseOptimizer:
"""Shared helpers for global parameter search algorithms."""
def __init__(self, env: DecisionEnv, config: BanditConfig) -> None:
self.env = env
self.config = config
self._random = random.Random(config.seed)
self._specs: List[ParameterSpec] = list(getattr(env, "_specs", []))
if not self._specs:
raise ValueError("DecisionEnv does not expose parameter specs")
self._value_estimates: Dict[Tuple[float, ...], float] = {}
self._counts: Dict[Tuple[float, ...], int] = {}
self._history = BanditSummary()
self._random = random.Random(config.seed)
def run(self) -> BanditSummary:
for episode in range(1, self.config.episodes + 1):
action = self._select_action()
def _evaluate_action(self, action: Sequence[float]) -> Tuple[float, EpisodeMetrics, Dict[str, float], Dict[str, Any]]:
self.env.reset()
done = False
cumulative_reward = 0.0
obs = {}
obs: Dict[str, float] = {}
info: Dict[str, Any] = {}
done = False
while not done:
obs, reward, done, info = self.env.step(action)
cumulative_reward += reward
metrics = self.env.last_metrics
if metrics is None:
raise RuntimeError("DecisionEnv did not populate last_metrics")
key = tuple(action)
old_estimate = self._value_estimates.get(key, 0.0)
count = self._counts.get(key, 0) + 1
self._counts[key] = count
self._value_estimates[key] = old_estimate + (cumulative_reward - old_estimate) / count
return cumulative_reward, metrics, obs, info
def _record_episode(
self,
action: Sequence[float],
reward: float,
metrics: EpisodeMetrics,
obs: Dict[str, float],
info: Dict[str, Any],
) -> None:
action_payload = self._raw_action_mapping(action)
resolved_action = self._resolved_action_mapping(action)
metrics_payload = _metrics_to_dict(metrics)
@ -100,7 +107,7 @@ class EpsilonGreedyBandit:
experiment_id=self.config.experiment_id,
strategy=self.config.strategy,
action=action_payload,
reward=cumulative_reward,
reward=reward,
metrics=metrics_payload,
weights=info.get("weights"),
)
@ -110,27 +117,13 @@ class EpsilonGreedyBandit:
episode_record = BanditEpisode(
action=action_payload,
resolved_action=resolved_action,
reward=cumulative_reward,
reward=reward,
metrics=metrics,
observation=obs,
weights=info.get("weights"),
department_controls=department_controls,
)
self._history.episodes.append(episode_record)
LOGGER.info(
"Bandit episode=%s reward=%.4f action=%s",
episode,
cumulative_reward,
action_payload,
extra=LOG_EXTRA,
)
return self._history
def _select_action(self) -> List[float]:
if self._value_estimates and self._random.random() > self.config.epsilon:
best = max(self._value_estimates.items(), key=lambda item: item[1])[0]
return list(best)
return [self._sample_value(spec) for spec in self._specs]
def _raw_action_mapping(self, action: Sequence[float]) -> Dict[str, float]:
return {
@ -144,13 +137,142 @@ class EpsilonGreedyBandit:
for spec, value in zip(self._specs, action, strict=True)
}
def _sample_value(self, spec: ParameterSpec) -> float:
def _sample_random_action(self) -> List[float]:
values: List[float] = []
for spec in self._specs:
if spec.values:
if len(spec.values) <= 1:
return 0.0
values.append(0.0)
else:
index = self._random.randrange(len(spec.values))
return index / (len(spec.values) - 1)
return self._random.random()
values.append(index / (len(spec.values) - 1))
else:
values.append(self._random.random())
return values
def _mutate_action(self, action: Sequence[float], scale: float = 0.1) -> List[float]:
mutated = []
for value in action:
jitter = self._random.gauss(0.0, scale)
mutated.append(min(1.0, max(0.0, float(value + jitter))))
return mutated
class EpsilonGreedyBandit(_BaseOptimizer):
"""Epsilon-greedy tuner using DecisionEnv as the reward oracle."""
def __init__(self, env: DecisionEnv, config: BanditConfig) -> None:
super().__init__(env, config)
self._value_estimates: Dict[Tuple[float, ...], float] = {}
self._counts: Dict[Tuple[float, ...], int] = {}
def run(self) -> BanditSummary:
for episode in range(1, self.config.episodes + 1):
action = self._select_action()
reward, metrics, obs, info = self._evaluate_action(action)
key = tuple(action)
old_estimate = self._value_estimates.get(key, 0.0)
count = self._counts.get(key, 0) + 1
self._counts[key] = count
self._value_estimates[key] = old_estimate + (reward - old_estimate) / count
self._record_episode(action, reward, metrics, obs, info)
LOGGER.info(
"Bandit episode=%s reward=%.4f action=%s",
episode,
reward,
self._raw_action_mapping(action),
extra=LOG_EXTRA,
)
return self._history
def _select_action(self) -> List[float]:
if self._value_estimates and self._random.random() > self.config.epsilon:
best = max(self._value_estimates.items(), key=lambda item: item[1])[0]
return list(best)
return self._sample_random_action()
class BayesianBandit(_BaseOptimizer):
"""Gaussian-process based Bayesian optimization."""
def __init__(self, env: DecisionEnv, config: BanditConfig) -> None:
super().__init__(env, config)
self._X: List[np.ndarray] = []
self._y: List[float] = []
self._noise = 1e-6
self._length_scale = 0.3
def run(self) -> BanditSummary:
for _ in range(self.config.episodes):
action = self._propose_action()
reward, metrics, obs, info = self._evaluate_action(action)
self._record_episode(action, reward, metrics, obs, info)
self._X.append(np.array(action, dtype=float))
self._y.append(reward)
return self._history
def _propose_action(self) -> List[float]:
if not self._X:
return self._sample_random_action()
X = np.vstack(self._X)
y = np.asarray(self._y, dtype=float)
K = self._kernel(X, X) + self._noise * np.eye(len(X))
try:
K_inv = np.linalg.inv(K)
except np.linalg.LinAlgError:
K_inv = np.linalg.pinv(K)
best_y = max(y)
candidates = [self._sample_random_action() for _ in range(self.config.candidate_pool)]
ei_values: List[Tuple[float, List[float]]] = []
for candidate in candidates:
x = np.asarray(candidate, dtype=float)
k_star = self._kernel(X, x[None, :])[:, 0]
mean = float(k_star @ K_inv @ y)
k_ss = float(self._kernel(x[None, :], x[None, :])[0, 0])
variance = max(k_ss - k_star @ K_inv @ k_star, 1e-9)
std = math.sqrt(variance)
improvement = mean - best_y - self.config.exploration_weight
z = improvement / std if std > 0 else 0.0
cdf = 0.5 * (1.0 + math.erf(z / math.sqrt(2.0)))
pdf = (1.0 / math.sqrt(2.0 * math.pi)) * math.exp(-0.5 * z * z)
ei = improvement * cdf + std * pdf if std > 0 else max(improvement, 0.0)
ei_values.append((ei, candidate))
ei_values.sort(key=lambda item: item[0], reverse=True)
best = ei_values[0][1] if ei_values else self._sample_random_action()
return best
def _kernel(self, x1: np.ndarray, x2: np.ndarray) -> np.ndarray:
sq_dist = np.sum((x1[:, None, :] - x2[None, :, :]) ** 2, axis=2)
return np.exp(-0.5 * sq_dist / (self._length_scale ** 2))
class SuccessiveHalvingOptimizer(_BaseOptimizer):
"""Simplified BOHB-style successive halving optimizer."""
def run(self) -> BanditSummary:
num_candidates = max(1, self.config.initial_candidates)
eta = max(2, self.config.eta)
actions = [self._sample_random_action() for _ in range(num_candidates)]
for round_idx in range(self.config.max_rounds):
if not actions:
break
evaluations: List[Tuple[float, List[float]]] = []
for action in actions:
reward, metrics, obs, info = self._evaluate_action(action)
self._record_episode(action, reward, metrics, obs, info)
evaluations.append((reward, action))
evaluations.sort(key=lambda item: item[0], reverse=True)
survivors = max(1, len(evaluations) // eta)
actions = [action for _, action in evaluations[:survivors]]
if len(actions) == 1:
break
actions = [self._mutate_action(action, scale=0.05 * (round_idx + 1)) for action in actions]
return self._history
def _metrics_to_dict(metrics: EpisodeMetrics) -> Dict[str, float | Dict[str, int]]:
@ -159,6 +281,7 @@ def _metrics_to_dict(metrics: EpisodeMetrics) -> Dict[str, float | Dict[str, int
"max_drawdown": metrics.max_drawdown,
"volatility": metrics.volatility,
"sharpe_like": metrics.sharpe_like,
"calmar_like": metrics.calmar_like,
"turnover": metrics.turnover,
"turnover_value": metrics.turnover_value,
"trade_count": float(metrics.trade_count),

View File

@ -638,6 +638,17 @@ def render_backtest_review() -> None:
help="可选:为本次调参记录一个策略名称或备注。",
)
strategy_choice = st.selectbox(
"搜索策略",
["epsilon_greedy", "bayesian", "bohb"],
format_func=lambda x: {
"epsilon_greedy": "Epsilon-Greedy",
"bayesian": "贝叶斯优化",
"bohb": "BOHB/Successive Halving",
}.get(x, x),
key="decision_env_search_strategy",
)
agent_objects = default_agents()
agent_names = [agent.name for agent in agent_objects]
if not agent_names:
@ -841,8 +852,23 @@ def render_backtest_review() -> None:
)
st.divider()
st.subheader("自动探索epsilon-greedy")
col_ep, col_eps, col_seed = st.columns([1, 1, 1])
st.subheader("全局参数搜索")
seed_text = st.text_input(
"随机种子(可选)",
value="",
key="decision_env_search_seed",
help="填写整数可复现实验,不填写则随机。",
).strip()
bandit_seed = None
if seed_text:
try:
bandit_seed = int(seed_text)
except ValueError:
st.warning("随机种子需为整数,已忽略该值。")
bandit_seed = None
if strategy_choice == "epsilon_greedy":
col_ep, col_eps = st.columns([1, 1])
bandit_episodes = int(
col_ep.number_input(
"迭代次数",
@ -865,21 +891,89 @@ def render_backtest_review() -> None:
help="ε 越大,随机探索概率越高。",
)
)
seed_text = col_seed.text_input(
"随机种子(可选)",
value="",
key="decision_env_bandit_seed",
help="填写整数可复现实验,不填写则随机。",
).strip()
bandit_seed = None
if seed_text:
try:
bandit_seed = int(seed_text)
except ValueError:
st.warning("随机种子需为整数,已忽略该值。")
bandit_seed = None
bayes_iterations = bandit_episodes
bayes_pool = 128
bayes_explore = 0.01
bohb_initial = 27
bohb_eta = 3
bohb_rounds = 3
elif strategy_choice == "bayesian":
col_ep, col_pool, col_xi = st.columns(3)
bayes_iterations = int(
col_ep.number_input(
"迭代次数",
min_value=3,
max_value=200,
value=15,
step=1,
key="decision_env_bayes_iterations",
)
)
bayes_pool = int(
col_pool.number_input(
"候选采样数",
min_value=16,
max_value=1024,
value=128,
step=16,
key="decision_env_bayes_pool",
)
)
bayes_explore = float(
col_xi.number_input(
"探索权重 ξ",
min_value=0.0,
max_value=0.5,
value=0.01,
step=0.01,
format="%.3f",
key="decision_env_bayes_xi",
)
)
bandit_episodes = bayes_iterations
bandit_epsilon = 0.0
bohb_initial = 27
bohb_eta = 3
bohb_rounds = 3
else: # bohb
col_init, col_eta, col_rounds = st.columns(3)
bohb_initial = int(
col_init.number_input(
"初始候选数",
min_value=3,
max_value=243,
value=27,
step=3,
key="decision_env_bohb_initial",
)
)
bohb_eta = int(
col_eta.number_input(
"压缩因子 η",
min_value=2,
max_value=6,
value=3,
step=1,
key="decision_env_bohb_eta",
)
)
bohb_rounds = int(
col_rounds.number_input(
"最大轮次",
min_value=1,
max_value=6,
value=3,
step=1,
key="decision_env_bohb_rounds",
)
)
bandit_episodes = bohb_initial
bandit_epsilon = 0.0
bayes_iterations = bandit_episodes
bayes_pool = 128
bayes_explore = 0.01
run_bandit = st.button("执行自动探索", key="run_decision_env_bandit")
run_bandit = st.button("执行参数搜", key="run_decision_env_bandit")
if run_bandit:
if not specs:
st.warning("请至少配置一个动作维度再执行探索。")
@ -912,13 +1006,24 @@ def render_backtest_review() -> None:
baseline_weights=baseline_weights,
disable_departments=disable_departments,
)
search_strategy = strategy_choice
config = BanditConfig(
experiment_id=experiment_id or f"bandit_{datetime.now().strftime('%Y%m%d_%H%M%S')}",
strategy=strategy_label or "DecisionEnv",
strategy=strategy_label or search_strategy,
episodes=bandit_episodes,
epsilon=bandit_epsilon,
seed=bandit_seed,
exploration_weight=bayes_explore,
candidate_pool=bayes_pool,
initial_candidates=bohb_initial,
eta=bohb_eta,
max_rounds=bohb_rounds,
)
if search_strategy == "bayesian":
bandit = BayesianBandit(env, config)
elif search_strategy == "bohb":
bandit = SuccessiveHalvingOptimizer(env, config)
else:
bandit = EpsilonGreedyBandit(env, config)
with st.spinner("自动探索进行中,请稍候..."):
summary = bandit.run()

View File

@ -22,7 +22,7 @@
| 强化学习基线 | ✅ | PPO/SAC 等连续动作算法已接入并形成实验基线。 |
| 奖励与评估体系 | 🔄 | 决策环境奖励已纳入风险/Turnover/Sharpe-Calmar待接入成交与资金曲线指标。 |
| 实时持仓链路 | ⏳ | 建立线上持仓/成交写入与离线调参与监控共享的数据源。 |
| 全局参数搜索 | ⏳ | 引入 Bandit、贝叶斯优化或 BOHB 提供权重/参数候选。 |
| 全局参数搜索 | 🔄 | 已上线 epsilon-greedy 调参与指标输出,后续补充贝叶斯优化 / BOHB。 |
## 多智能体协同与 LLM

View File

@ -1,10 +1,15 @@
"""Tests for epsilon-greedy bandit optimizer."""
"""Tests for global parameter search optimizers."""
from __future__ import annotations
import pytest
from app.backtest.decision_env import EpisodeMetrics, ParameterSpec
from app.backtest.optimizer import BanditConfig, EpsilonGreedyBandit
from app.backtest.optimizer import (
BanditConfig,
EpsilonGreedyBandit,
BayesianBandit,
SuccessiveHalvingOptimizer,
)
from app.utils import tuning
@ -84,11 +89,11 @@ def patch_logging(monkeypatch):
return records
def test_bandit_optimizer_runs_and_logs(patch_logging):
def test_epsilon_greedy_optimizer(patch_logging):
env = DummyEnv()
optimizer = EpsilonGreedyBandit(
env,
BanditConfig(experiment_id="exp", episodes=5, epsilon=0.5, seed=42),
BanditConfig(experiment_id="exp_eps", episodes=5, epsilon=0.5, seed=42),
)
summary = optimizer.run()
@ -98,8 +103,42 @@ def test_bandit_optimizer_runs_and_logs(patch_logging):
payload = patch_logging[0]["metrics"]
assert isinstance(payload, dict)
assert "risk_breakdown" in payload
assert "department_controls" in payload
assert summary.best_episode.department_controls == {"momentum": {"prompt": "baseline"}}
first_episode = summary.episodes[0]
assert first_episode.resolved_action
assert first_episode.department_controls == {"momentum": {"prompt": "baseline"}}
def test_bayesian_optimizer(patch_logging):
env = DummyEnv()
optimizer = BayesianBandit(
env,
BanditConfig(
experiment_id="exp_bayes",
strategy="bayesian",
episodes=6,
candidate_pool=32,
exploration_weight=0.01,
seed=123,
),
)
summary = optimizer.run()
assert summary.best_episode is not None
assert summary.best_episode.reward > 0.3
assert len(patch_logging) >= 6
def test_successive_halving_optimizer(patch_logging):
env = DummyEnv()
optimizer = SuccessiveHalvingOptimizer(
env,
BanditConfig(
experiment_id="exp_bohb",
strategy="bohb",
initial_candidates=9,
eta=3,
max_rounds=2,
seed=7,
),
)
summary = optimizer.run()
assert summary.best_episode is not None
assert summary.best_episode.reward > 0.3
assert len(patch_logging) >= 9