# coding=utf-8
# ======================================
# File: optimization.py
# Author: Jackie PENG
# Contact: jackie.pengzhao@gmail.com
# Created: 2024-03-12
# Desc:
# Core functions for strategy optimization
# and parameter searching
# ======================================
import random
import pandas as pd
import numpy as np
import time
import logging
from typing import Union, Optional, Generator
from tqdm import tqdm
from concurrent.futures import ProcessPoolExecutor, as_completed
from qteasy.qt_operator import (
Operator,
SIGNAL_TYPE_ID,
)
from qteasy.backtest import (
Backtester,
generate_cash_invest_and_delivery_arrays,
backtest_flash_steps,
)
from qteasy.history import (
HistoryPanel,
stack_dataframes,
)
from qteasy.utilfuncs import (
sec_to_duration,
str_to_list,
)
from qteasy.space import (
Space,
ResultPool,
)
from qteasy.finance import (
CashPlan,
)
def _gp_predict_rbf(
X_train: np.ndarray,
y_train: np.ndarray,
X_test: np.ndarray,
length_scale: Optional[float] = None,
noise: float = 1e-5,
) -> tuple[Optional[np.ndarray], Optional[np.ndarray]]:
"""使用 RBF 核的高斯过程回归,对 X_test 预测均值和标准差(仅用 numpy)。
Parameters
----------
X_train : np.ndarray
已评估点的编码矩阵,形状 (n, d)。
y_train : np.ndarray
已评估点的目标值,形状 (n,)。
X_test : np.ndarray
待预测点的编码矩阵,形状 (m, d)。
length_scale : float, optional
RBF 核长度尺度;None 时取训练点两两距离中位数的 0.5 倍。
noise : float
观测噪声方差,用于数值稳定。
Returns
-------
mu : np.ndarray or None
预测均值,形状 (m,);拟合失败时返回 None。
sigma : np.ndarray or None
预测标准差,形状 (m,);拟合失败时返回 None。
"""
X_train = np.asarray(X_train, dtype=float)
y_train = np.asarray(y_train, dtype=float).ravel()
X_test = np.asarray(X_test, dtype=float)
n, d = X_train.shape
if n == 0 or y_train.size != n:
return None, None
if length_scale is None and n >= 2:
dists = []
for i in range(n):
for j in range(i + 1, n):
dists.append(np.sqrt(np.sum((X_train[i] - X_train[j]) ** 2)))
length_scale = float(np.median(dists)) * 0.5 if dists else 1.0
if length_scale is None or length_scale <= 0:
length_scale = 1.0
ls = length_scale
# K = RBF(X_train, X_train) + noise * I
sqdist = np.sum(X_train ** 2, axis=1, keepdims=True) - 2 * (X_train @ X_train.T) + np.sum(X_train ** 2, axis=1)
sqdist = np.maximum(sqdist, 0.0)
K = np.exp(-0.5 * sqdist / (ls ** 2)) + noise * np.eye(n)
try:
L = np.linalg.cholesky(K)
except np.linalg.LinAlgError:
return None, None
alpha = np.linalg.solve(L.T, np.linalg.solve(L, y_train))
# k*: (m, n)
sqdist_star = np.sum(X_test ** 2, axis=1, keepdims=True) - 2 * (X_test @ X_train.T) + np.sum(X_train ** 2, axis=1)
sqdist_star = np.maximum(sqdist_star, 0.0)
k_star = np.exp(-0.5 * sqdist_star / (ls ** 2))
mu = k_star @ alpha
v = np.linalg.solve(L, k_star.T)
k_star_star = np.ones((X_test.shape[0],))
sigma_sq = np.maximum(k_star_star - np.sum(v ** 2, axis=0), 1e-12)
sigma = np.sqrt(sigma_sq)
return mu, sigma
_shared_op: Optional[Operator] = None
_shared_cash_investment_array: Optional[np.ndarray] = None
_shared_cash_inflation_array: Optional[np.ndarray] = None
_shared_delivery_day_indicators: Optional[np.ndarray] = None
_shared_trade_price_data: Optional[np.ndarray] = None
# TODO: 这个函数有潜在大量运行的可能,需要使用Numba加速
def _create_mock_data(history_data: HistoryPanel) -> HistoryPanel:
""" 根据输入的历史数据的统计特征,随机生成多组具备同样统计特征的随机序列,用于进行策略收益的蒙特卡洛模拟
目前仅支持OHLC数据以及VOLUME数据的随机生成,其余种类的数据需要继续研究
为了确保生成的数据留有足够的前置数据窗口,生成的伪数据包含两段,第一段长度与最大前置窗口长度相同,这一段
为真实历史数据,第二段才是随机生成的模拟数据
同时,生成的数据仍然满足OHLC的关系,同时所有的数据在统计上与参考数据是一致的,也就是说,随机生成的数据
不仅仅满足K线图的形态要求,其各个参数的均值、标准差与参考数据一致。
Parameters
----------
history_data: HistoryPanel
模拟数据的参考源
Returns
-------
HistoryPanel
"""
assert isinstance(history_data, HistoryPanel)
data_types = history_data.htypes
# TODO: volume数据的生成还需要继续研究
assert any(data_type in ['close', 'open', 'high', 'low', 'volume'] for data_type in data_types), \
f'the data type {data_types} does not fit'
has_volume = any(data_type in ['volume'] for data_type in data_types)
# 按照细粒度方法同时生成OHLC数据
# 针对每一个share生成OHLC数据
# 先考虑生成正确的信息,以后再考虑优化
dfs_for_share = []
for share in history_data.shares:
share_df = history_data.slice_to_dataframe(share=share)
share_df['close_chg'] = share_df.close / share_df.close.shift(1)
mean = share_df.close_chg.mean()
std = share_df.close_chg.std()
mock_col = np.random.randn(len(history_data.hdates) * 5) * std * 5 + mean
mock_col = 1 + 0.09 * (mock_col - 1)
mock_col[0] = share_df.close.iloc[0]
mock_col = np.cumprod(mock_col)
mock = mock_col.reshape(len(history_data.hdates), 5)
mock_df = pd.DataFrame(index=history_data.hdates)
mock_df['open'] = mock[:, 0]
mock_df['high'] = np.max(mock, axis=1)
mock_df['low'] = np.min(mock, axis=1)
mock_df['close'] = mock[:, 4]
if has_volume:
mock_df['volume'] = share_df.volume
dfs_for_share.append(mock_df.copy())
# 生成一个HistoryPanel对象,每一层一个个股
mock_data = stack_dataframes(dfs_for_share,
dataframe_as='shares',
shares=history_data.shares)
return mock_data
def _initialize_worker(op,
cash_investment_array,
cash_inflation_array,
delivery_day_indicators,
trade_price_data,
) -> None:
""" Initialize shared memory for parallel workers"""
global _shared_op, _shared_cash_inflation_array, _shared_cash_investment_array, \
_shared_delivery_day_indicators, _shared_trade_price_data
_shared_op = op
_shared_cash_investment_array = cash_investment_array
_shared_cash_inflation_array = cash_inflation_array
_shared_delivery_day_indicators = delivery_day_indicators
_shared_trade_price_data = trade_price_data
def _flash_evaluate_parameter(
share_count,
cost_params,
signal_parsing_params,
trading_moq_params,
trading_delivery_params,
par_values: tuple,
) -> float:
""" 本质上实现了与_evaluate_parameter相同的功能,但不使用Backtester对象进行回测,
而是直接调用Operator的信号生成,同时调用backtest.backtest_batch_steps()函数进行回测。
以降低多进程计算时Backtester对象传输的开销。
Parameters
----------
par_values: tuple
策略参数值元组,元组中的每一个值对应策略空间中的一个参数
Returns
-------
result: float
策略参数对应的回测结果评分
"""
global _shared_op, _shared_cash_inflation_array, _shared_cash_investment_array, \
_shared_delivery_day_indicators, _shared_trade_price_data
_shared_op.set_opt_par_values(par_values=par_values)
# 1,调用operator.run()生成完整的交易信号清单,并计算保存运行时间
signal_length = _shared_op.get_signal_count()
stypes = np.zeros(signal_length, dtype=int)
s_indices = np.zeros(signal_length, dtype=int)
signals = np.zeros((signal_length, share_count), dtype=float)
signal_index = 0
for stype, s_index, signal in _shared_op.run_strategies(steps=range(len(_shared_op.group_timing_table))):
stypes[signal_index] = SIGNAL_TYPE_ID[stype]
s_indices[signal_index] = s_index
signals[signal_index, :] = signal
signal_index += 1
# 3,调用backtest_batch_steps()进行回测,填充回测结果清单
closing_cash, closing_amounts = backtest_flash_steps(
signal_types=stypes,
op_signals=signals,
cash_investment_array=_shared_cash_investment_array,
cash_inflation_array=_shared_cash_inflation_array,
delivery_day_indicators=_shared_delivery_day_indicators,
trade_prices=_shared_trade_price_data,
cost_params=cost_params,
**signal_parsing_params,
**trading_moq_params,
**trading_delivery_params,
)
# DEBUG
# print(f'evaluating parameter in op {id(op)} with trade_price_data: {id(trade_price_data)}')
opti_target = 'fv'
if opti_target == 'fv':
result = (_shared_trade_price_data[-1] * closing_amounts).sum() + closing_cash
elif opti_target == 'vol':
raise NotImplementedError('Volatility calculation without Backtester is not implemented yet')
elif opti_target == 'mdd':
raise NotImplementedError('Max Drawdown calculation without Backtester is not implemented yet')
else:
raise ValueError(f'Unsupported optimization target: {opti_target}')
return result
[文档]class Optimizer:
""" 最优参数搜索器对象
"""
def __init__(self,
*,
op: Operator,
method: str,
shares: list[str],
benchmark: pd.DataFrame,
pool_size: int,
opti_target: str,
opti_direction: str,
parallel: bool,
opti_start_date: str,
opti_end_date: str,
test_start_date: str,
test_end_date: str,
opti_cash_plan: CashPlan,
test_cash_plan: CashPlan,
cost_params: np.ndarray, # 交易成本参数
signal_parsing_params: dict, # 交易信号解析参数
trading_moq_params: dict, # 交易最小单位参数
trading_delivery_params: dict, # 交易交割参数
search_config: dict,
logger: Optional[logging.Logger] = None,
evaluate_indicators: str = 'r,m,v,b',
test_plot_type: str = 'histo'):
"""初始化Optimizer对象,设置基本参数
Parameters
----------
op: Operator
交易操作对象,包含交易信号生成和交易执行的逻辑
method: str
优化方法名称,目前支持的优化方法包括:
'grid':网格搜索法
'montecarlo':蒙特卡洛法
'incremental':增量递进搜索法
'ga':遗传算法
'gradient':梯度下降法
'pso':粒子群优化算法
'aco':蚁群优化算法
shares: list[str]
交易标的列表,包含所有交易标的的代码
benchmark: str
交易业绩评价基准数据类型,一个股票代码或基金代码
pool_size: int
优化结果池的大小,表示在优化过程中保存的最佳参数组合数量
opti_target: str
优化目标名称,用于指定优化过程中需要最大化或最小化的性能指标
opti_direction: str
优化方向,取值为 'maximize' 或 'minimize',表示优化目标是最大化还是最小化
opti_start_date: str
优化区间开始日期,格式为 'YYYY-MM-DD' 或 'YYYYMMDD'
opti_end_date: str
优化区间结束日期,格式为 'YYYY-MM-DD' 或 'YYYYMMDD'
test_start_date: str
测试区间开始日期,格式为 'YYYY-MM-DD' 或 'YYYYMMDD'
test_end_date: str
测试区间结束日期,格式为 'YYYY-MM-DD' 或 'YYYYMMDD'
opti_cash_plan: CashPlan,
现金投资计划
test_cash_plan: CashPlan,
现金投资计划
cost_params: np.ndarray
交易成本参数,包括买入费率、卖出费率、最低买入费用、最低卖出费用、交易滑点
buy_rate: float, 交易成本:固定买入费率
sell_rate: float, 交易成本:固定卖出费率
buy_min: float, 交易成本:最低买入费用
sell_min: float, 交易成本:最低卖出费用
slippage: float, 交易成本:滑点
signal_parsing_params: dict
交易信号解析参数字典,包含解析交易信号所需的所有参数,通常是parse_signal_parsing_params()函数的输出
trading_moq_params: dict
交易最小单位参数字典,包含交易最小单位相关的所有参数,通常是parse_trading_moq_params()函数的输出
trading_delivery_params: dict
交易交割参数字典,包含交易交割相关的所有参数,通常是parse_trading_delivery_params()函数的输出
logger: Optional[logging.Logger]
可选的日志记录器对象,用于记录回测过程中的日志信息
evaluate_indicators: Optional[str], default 'r,m,v,b'
优化结果评价指标清单
test_plot_type: Optional[str], default 'histo'
优化结果图表显示类型
"""
# 参数基础校验
assert isinstance(op, Operator), "op must be an instance of Operator"
if isinstance(shares, str):
shares = str_to_list(shares)
assert isinstance(shares, list) and all(isinstance(s, str) for s in shares), "shares must be a list of strings"
if not isinstance(method, str):
raise ValueError("method must be a string")
if method not in self.AVAILABLE_OPTIMIZERS:
raise ValueError(
f"method {method} is not supported. Available methods are: {list(self.AVAILABLE_OPTIMIZERS.keys())}")
if not isinstance(pool_size, int) or pool_size <= 0:
raise ValueError("pool_size must be a positive integer")
if opti_direction not in ['maximize', 'minimize']:
raise ValueError("opti_direction must be either 'maximize' or 'minimize'")
if opti_target not in ['fv', 'vol', 'mdd']:
raise ValueError("opti_target must be a valid performance metric: 'fv', 'vol', or 'mdd'")
# 1,所有基本属性
self.opti_method = method
# self.opti_func = self.AVAILABLE_OPTIMIZERS[method]
self.op = op
self.op_signals: Optional[np.ndarray] = None # 回测生成的交易信号表格,实际上在op内也可以存储
self.shares = shares
self.share_count = len(shares)
self.benchmark = benchmark
self.opti_method = method.lower()
self.opti_target = opti_target
self.opti_direction = opti_direction
self.opti_start = opti_start_date
self.opti_end = opti_end_date
self.test_start = test_start_date
self.test_end = test_end_date
self.opti_cash_plan = opti_cash_plan
self.test_cash_plan = test_cash_plan
self.cost_params = cost_params
self.signal_parsing_params = signal_parsing_params
self.trading_moq_params = trading_moq_params
self.trading_delivery_params = trading_delivery_params
self.logger = logger
# 2,回测器属性以及用于回测器的中间参数
self.cash_investment_array = None # 现金投入数组
self.cash_inflation_array = None # 现金通胀数组
self.delivery_day_indicators = None # 交割日指标数组
self.trade_price_data: Optional[np.ndarray] = None # 回测使用的价格数据数组
self.running_backtester: Optional[Backtester] = None # 优化区间或验证区间回测器对象
# 优化配置属性
self.search_config = search_config
self.evaluate_indicators = evaluate_indicators
self.test_plot_type = test_plot_type
# 用于存储优化结果参数的属性
self.result_pool = ResultPool(capacity=pool_size)
self.result_pool_size = pool_size # 优化结果池的大小
self.validated_pool = ResultPool(capacity=pool_size)
self.parallel = parallel # 是否启用多进程计算方式
self.current_parameters = None # 当前优化参数
self.best_parameters = None # 最佳优化参数
self.best_performance = None # 最佳性能评分
self.opti_time = 0.0 # 优化时间记录
self.eval_time = 0.0 # 优化结果评价时间记录
self.test_time = 0.0 # 测试时间记录
def generate_running_backtester(self,
stage: str,
benchmark_data: pd.DataFrame,
trade_price_data: np.ndarray) -> None:
""" 根据指定的阶段生成对应的Backtester回测器对象
Parameters
----------
stage: str
回测阶段,取值为 'optimization' 或 'validation',分别表示优化区间回测器和验证区间回测器
benchmark_data: pd.DataFrame
交易业绩评价基准数据,一组与输出信号等时段的价格变动表或收益率变动表
trade_price_data: np.ndarray
交易价格数据数组,用于回测的价格数据
Returns
-------
None,生成的Backtester对象会被存储在self.running_backtester属性中
"""
if stage == 'optimization':
cash_plan = self.opti_cash_plan
elif stage == 'validation':
cash_plan = self.test_cash_plan
else:
raise ValueError(f'Unsupported stage: {stage}')
# 现金投入和交割数据表
(self.cash_investment_array,
self.cash_inflation_array,
self.delivery_day_indicators) = generate_cash_invest_and_delivery_arrays(
invest_cash_plan=cash_plan,
group_merge_type=self.op.group_merge_type,
timing_table=self.op.group_timing_table,
)
self.running_backtester = Backtester(
op=self.op,
shares=self.shares,
cash_plan=cash_plan,
cash_investment_array=self.cash_investment_array,
cash_inflation_array=self.cash_inflation_array,
delivery_day_indicators=self.delivery_day_indicators,
cost_params=self.cost_params,
signal_parsing_params=self.signal_parsing_params,
trading_moq_params=self.trading_moq_params,
trading_delivery_params=self.trading_delivery_params,
trade_price_data=trade_price_data,
benchmark_data=benchmark_data,
logger=self.logger,
)
def optimize(self,
benchmark_data: pd.DataFrame,
trade_price_data: np.ndarray) -> 'Optimizer':
self.op.set_shares(self.shares)
self.op.is_ready(raise_error=True)
# 创建一个Backtester对象用于优化区间的回测
self.trade_price_data = trade_price_data
self.generate_running_backtester(
stage='optimization',
benchmark_data=benchmark_data,
trade_price_data=trade_price_data,
)
self.result_pool.clear()
s_ranges, s_types = self.op.opt_space_par
search_space = Space(*s_ranges,
par_types=s_types) # 生成参数空间
st = time.time()
if self.opti_method == 'grid':
self._search_grid(space=search_space)
elif self.opti_method == 'montecarlo':
self._search_montecarlo(space=search_space)
elif self.opti_method == 'sa':
self._search_sa(space=search_space)
elif self.opti_method == 'ga':
self._search_ga(space=search_space)
elif self.opti_method == 'pso':
self._search_pso(space=search_space)
elif self.opti_method == 'gradient':
self._search_gradient(space=search_space)
elif self.opti_method == 'bayesian':
self._search_bayesian(space=search_space)
else:
raise ValueError(f'Unsupported optimization method: {self.opti_method}')
self.opti_time = time.time() - st
# deep evaluate all selected parameters on test set
par_value_list = self.result_pool.items
total = self.result_pool_size
self.result_pool.clear()
st = time.time()
self._evaluate_parameters(
total=total,
par_value_list=par_value_list,
result_pool=self.result_pool,
parallel=self.parallel,
deep_eval=True,
)
self.eval_time = time.time() - st
return self
def validate(self,
benchmark_data: pd.DataFrame,
trade_price_data: np.ndarray) -> 'Optimizer':
self.op.set_shares(self.shares)
self.op.is_ready(raise_error=True)
# 创建一个Backtester对象用于验证区间的回测
self.trade_price_data = trade_price_data
self.generate_running_backtester(
stage='validation',
benchmark_data=benchmark_data,
trade_price_data=trade_price_data,
)
self.validated_pool.clear()
optimized_par_list = self.result_pool.items.copy()
total = self.result_pool_size
st = time.time()
self._evaluate_parameters(
total=total,
par_value_list=optimized_par_list,
result_pool=self.validated_pool,
parallel=self.parallel,
deep_eval=True,
)
self.test_time = time.time() - st
return self
def _evaluate_parameter(self, par_values: tuple) -> float:
""" 使用一组策略参数进行回测,并返回回测结果的简易评价结果即一个数字评分
Parameters
----------
par_values: tuple
策略参数值元组,元组中的每一个值对应策略空间中的一个参数
Returns
-------
result: float
策略参数对应的回测结果评分
"""
self.op.set_opt_par_values(par_values=par_values)
# 在优化区间进行回测
self.running_backtester.run()
# DEBUG
# print(f'evaluating parameter in {id(self)} with backtester: {id(self.running_backtester)}')
if self.opti_target == 'fv':
result = self.running_backtester.trade_result_final_value()
elif self.opti_target == 'vol':
result = self.running_backtester.trade_result_volatility()
elif self.opti_target == 'mdd':
result = self.running_backtester.trade_result_max_drawdown()
else:
raise ValueError(f'Unsupported optimization target: {self.opti_target}')
return result
def _deep_evaluate_parameter(self, par_values: tuple) -> tuple[float, dict]:
""" 使用一组策略参数进行回测,并返回回测结果的数字评价结果及评价指标字典
Parameters
----------
par_values: tuple
策略参数值元组,元组中的每一个值对应策略空间中的一个参数
Returns
-------
"""
perf = self._evaluate_parameter(par_values)
metrics = self.running_backtester.evaluate_result(indicators=self.evaluate_indicators)
# 特殊处理回测评价结果,使其符合优化结果表的生成需要
metrics_to_pop = ['peak_date', 'valley_date', 'recover_date',
'worst_drawdowns', 'return_df', 'skew', 'kurtosis']
for metric in metrics_to_pop:
if metric in metrics.keys():
metrics.pop(metric)
if 'oper_count' in metrics.keys():
oper_count = metrics.pop('oper_count')
metrics['sell_count'] = oper_count.sell.sum()
metrics['buy_count'] = oper_count.buy.sum()
else:
metrics['sell_count'] = 0
metrics['buy_count'] = 0
metrics['par'] = par_values
return perf, metrics.copy()
def _evaluate_parameters(self,
total: int,
par_value_list: Union[list, tuple, Generator],
result_pool: ResultPool,
parallel: bool,
epoch_str: str = '1/1',
deep_eval: bool = False,
leave_progress_bar: bool = True) -> None:
""" 循环批量运行self._evaluate_parameter函数,生成结果后存入参数result_pool中
Parameters
----------
total: int
参数组合总数量,用于进度条显示
par_value_list: list/tuple/Generator
策略参数值列表或生成器,列表或生成器中的每一个元素都是一组策略参数值元组
result_pool: ResultPool
结果池对象,用于存储所有参数组合及其对应的评价结果
parallel: bool
是否启用多进程计算方式,如果是True,则启用多进程计算方式利用所有的CPU核心计算,
否则使用单进程计算
epoch_str: optional str
用于显示当前优化轮次的标识字符串,默认值为空字符串
deep_eval: optional bool
是否深入评价每一组参数的回测结果,如果是True,则返回评价指标字典,默认值为False
leave_progress_bar: optional bool, default True
是否在完成后保留进度条显示,默认值为True,对于多轮优化过程需要设置为False以减少屏幕输出
Returns
-------
pool,一个Pool对象,包含经过筛选后的所有策略参数以及它们的性能表现
"""
# DEBUG
# import tracemalloc
# tracemalloc.start()
# 启用多进程计算方式利用所有的CPU核心计算
if parallel:
# 启用并行计算
self._evaluate_parameters_parallel(
total=total,
par_value_list=par_value_list,
result_pool=result_pool,
epoch_str=epoch_str,
deep_eval=deep_eval,
leave_progress_bar=leave_progress_bar,
)
# 禁用多进程计算方式,使用单进程计算
else:
self._evaluate_parameters_sequential(
total=total,
par_value_list=par_value_list,
result_pool=result_pool,
epoch_str=epoch_str,
deep_eval=deep_eval,
leave_progress_bar=leave_progress_bar,
)
# DEBUG
# current, peak = tracemalloc.get_traced_memory()
# print(f"Current memory usage {current / 1e6}MB; Peak: {peak / 1e6}MB")
# tracemalloc.stop()
def _evaluate_parameters_parallel(self,
total: int,
par_value_list: Union[list, tuple, Generator],
result_pool: ResultPool,
epoch_str: str,
deep_eval: bool,
leave_progress_bar: bool) -> None:
""" 并行循环批量运行evaluate_parameters()并将结果存入result_pool
"""
i = 0
best_so_far = 0
# TODO: 在parallel的情况下,不管是使用flash_evaluate函数还是使用Backtester,在实际执行过程中都会
# 出现overhead开销过大的问题,影响整体计算效率,同时导致pbar无法显示(提交完成后,计算早就全部完成了
# ),试过使用函数代替Backtester或减少内存消耗量,但是无济于事,最终结果都一样。最后一个办法是使用
# SharedMemory来实现函数调用,需要探索
eval_func = self._deep_evaluate_parameter if deep_eval else self._evaluate_parameter
pbar_position = 1 if not leave_progress_bar else 0
# 启用并行计算
with ProcessPoolExecutor() as proc_pool:
futures = {proc_pool.submit(eval_func, par): par for par in
par_value_list}
with tqdm(total=total, leave=leave_progress_bar, position=pbar_position) as pbar:
for f in as_completed(futures):
target_value = f.result()
if deep_eval:
perf, metrics = target_value
else:
perf, metrics = target_value, None
result_pool.push(item=futures[f], perf=perf, extra=metrics)
i += 1
if perf > best_so_far:
best_so_far = perf
pbar.set_description(desc=f'Epoch:{epoch_str}->{best_so_far:.3f}', )
pbar.update()
def _evaluate_parameters_sequential(self,
total: int,
par_value_list: Union[list, tuple, Generator],
result_pool: ResultPool,
epoch_str: str,
deep_eval: bool,
leave_progress_bar: bool) -> None:
""" 顺序循环运行evaluate_parameters()方法,并将结果存入result_pool
"""
i = 0
best_so_far = 0
eval_func = self._deep_evaluate_parameter if deep_eval else self._evaluate_parameter
pbar_position = 1 if not leave_progress_bar else 0
with tqdm(total=total, leave=leave_progress_bar, position=pbar_position) as pbar:
for par in par_value_list:
self.running_backtester.clear_backtest_buffers()
target_value = eval_func(par)
if deep_eval:
perf, metrics = self._deep_evaluate_parameter(par)
else:
perf, metrics = target_value, None
result_pool.push(item=par, perf=perf, extra=metrics)
i += 1
if perf > best_so_far:
best_so_far = perf
pbar.set_description(desc=f'Epoch:{epoch_str}->{best_so_far:.3f}', )
pbar.update(1)
def _search_grid(self,
space: Space) -> None:
"""网格搜索:在参数空间上按固定步长取样并批量评估。
Parameters
----------
space : Space
待搜索的参数空间。
Returns
-------
None
最优结果写入 ``self.result_pool``。
"""
# 使用extract从参数空间中提取所有的点,并打包为iterator对象进行循环
par_generator, total = space.extract(self.search_config['sample_count'])
self._evaluate_parameters(
total=total,
par_value_list=par_generator,
result_pool=self.result_pool,
parallel=self.parallel
)
self.result_pool.cut(keep_largest=self.search_config['maximize_target'])
def _search_montecarlo(self,
space: Space) -> None:
"""蒙特卡洛随机搜索:在 ``space`` 内均匀随机取样并批量评估。
Parameters
----------
space : Space
待搜索的参数空间。
Returns
-------
None
最优结果写入 ``self.result_pool``。
"""
# 使用随机方法从参数空间中取出point_count个点,并打包为iterator对象,后面的操作与网格法一致
par_generator, total = space.extract(self.search_config['sample_count'], how='rand')
self._evaluate_parameters(
total=total,
par_value_list=par_generator,
result_pool=self.result_pool,
parallel=self.parallel
)
self.result_pool.cut(self.search_config['maximize_target'])
def _search_sa(self,
space: Space) -> None:
"""递进步长式随机搜索:多轮蒙特卡洛 + 子空间收缩。
每轮在若干子空间内随机采样,择优后用 ``reduce_ratio`` 等配置收缩邻域并进入下一轮,
直至达到 ``min_volume`` 或 ``max_rounds`` 等停止条件。
Parameters
----------
space : Space
初始参数空间。
Returns
-------
None
最优结果写入 ``self.result_pool``。
"""
sample_count = self.search_config['opti_r_sample_count']
min_volume = self.search_config['opti_min_volume']
max_rounds = self.search_config['opti_max_rounds']
reduce_ratio = self.search_config['opti_reduce_ratio']
parallel = self.parallel
spaces = list() # 子空间列表,用于存储中间结果邻域子空间,邻域子空间数量与pool中的元素个数相同
base_space = space
base_dimension = base_space.dim
# 每一轮参数寻优后需要保留的参数组的数量
self.result_pool.capacity = sample_count # 临时修改参数池的大小为reduced_sample_count
spaces.append(base_space) # 将整个空间作为第一个子空间对象存储起来
space_count_in_round = 1 # 本轮运行子空间的数量
current_round = 0 # 当前运行轮次
current_volume = base_space.volume # 当前运行轮次子空间的总体积
"""
估算运行的总回合数量,由于每一轮运行的回合数都是大致固定的(随着空间大小取整会有波动)
因此总的运行回合数就等于轮数乘以每一轮的回合数。关键是计算轮数
由于轮数的多少取决于两个变量,一个是最大轮次数,另一个是下一轮产生的子空间总和体积是否
小于最小体积阈值,因此,推算过程如下:
设初始空间体积为Vi,最小空间体积为Vmin,每一轮的缩小率为rr,最大计算轮数为Rmax
且第k轮的空间体积为Vk,则有:
Vk = Vi * rr ** k
停止条件1: Vk = Vi * rr ** k < Vmin
停止条件2: k >= Rmax
根据停止条件1: rr ** k < Vmin / Vi
k > log(Vmin / Vi) / log(rr)
因此,当: k > min(Rmax, log(Vmin / Vi) / log(rr))
"""
# 从当前space开始搜索,当subspace的体积小于min_volume或循环次数达到max_rounds时停止循环
while current_volume >= min_volume and current_round < max_rounds:
# 在每一轮循环中,spaces列表存储该轮所有的空间或子空间
par_list = list()
round_total = 0
for space in spaces:
# 逐个弹出子空间列表中的子空间,随机选择参数,生成参数生成器generator
# 生成的所有参数及评价结果压入pool结果池,每一轮所有空间遍历完成后再排序择优
par_generator, total = space.extract(sample_count // space_count_in_round, how='rand')
par_list.extend(par_generator)
round_total += total
self._evaluate_parameters(
total=round_total,
par_value_list=par_list,
result_pool=self.result_pool,
parallel=parallel,
epoch_str=f'{current_round + 1}/{max_rounds}',
)
self.result_pool.cut(self.search_config['maximize_target'])
"""
为了生成新的子空间,计算下一轮子空间的半径大小
为确保下一轮的子空间总体积与本轮子空间总体积的比值是reduce_ratio,需要根据空间的体积公式设置正确
的缩小比例。这个比例与空间的维数和子空间的数量有关
例如:
若 reduce_ratio(rr)=0.5,设初始空间体积为Vi,边长为Si,第k轮空间体积为Vk,子空间数量为m,
每个子空间的体积为V,Size为S,空间的维数为d,则有:
Si ** d * (rr ** k) = Vi * (rr ** k) = Vk = V * m = S ** d * m
于是:
S ** d * m = Si ** d * (rr ** k)
(S/Si) ** d = (rr ** k) / m
S/Si = ((rr ** k) / m) ** (1/d)
根据上述结果,第k轮的子空间直径S可以由原始空间的半径Si得到:
S = Si * ((rr ** k) / m) ** (1/d)
distance = S / 2
"""
size_reduce_ratio = ((reduce_ratio ** current_round) / sample_count) ** (1 / base_dimension)
reduced_size = tuple(np.array(base_space.size) * size_reduce_ratio / 2)
# 完成一轮搜索后,检查pool中留存的所有点,并生成由所有点的邻域组成的子空间集合
current_volume = 0
spaces.clear()
for point in self.result_pool.items:
subspace = base_space.from_point(point=point, distance=reduced_size)
spaces.append(subspace)
current_volume += subspace.volume
current_round += 1
space_count_in_round = len(spaces)
self.result_pool.capacity = self.result_pool_size
self.result_pool.cut(self.search_config['maximize_target'])
def _search_ga(self,
space: Space) -> None:
""" 最优参数搜索算法4: 遗传算法
遗传算法适用于在超大的参数空间内搜索全局最优或近似全局最优解,而它的计算量又处于可接受的范围内
遗传算法借鉴了生物的遗传迭代过程,首先在参数空间中随机选取一定数量的参数点,将这批参数点称为
“种群”。随后在这一种群的基础上进行迭代计算。在每一次迭代(称为一次繁殖)前,根据种群中每个个体
的评价函数值,确定每个个体生存或死亡的几率,规律是若个体的评价函数值越接近最优值,则其生存的几率
越大,繁殖后代的几率也越大,反之则越小。确定生死及繁殖的几率后,根据生死几率选择一定数量的个体
让其死亡,而从剩下的(幸存)的个体中根据繁殖几率挑选几率最高的个体进行杂交并繁殖下一代个体,
同时在繁殖的过程中引入随机的基因变异生成新的个体。最终使种群的数量恢复到初始值。这样就完成
一次种群的迭代。重复上面过程数千乃至数万代直到种群中出现希望得到的最优或近似最优解为止
Parameters
----------
space: qt.Space
参数空间对象
Returns
-------
None,搜索的结果最佳值会被保存在self.result_pool属性中
"""
population_size = self.search_config['population_size']
max_generations = self.search_config['max_generations']
maximize_target = self.search_config['maximize_target']
parallel = self.parallel
# 常量:变异率、交叉时从父代取段的概率、选择比例
mutation_rate = 0.1
select_top_ratio = 0.5
par_iter, total = space.extract(population_size, how='rand')
pop = list(par_iter)
if len(pop) < 2:
# 空间过小无法交叉时仅评估并写入 result_pool
self._evaluate_parameters(
total=len(pop),
par_value_list=pop,
result_pool=self.result_pool,
parallel=parallel,
)
self.result_pool.cut(keep_largest=maximize_target)
return
sizes = space.vector_axis_sizes
dim = space.dim
offsets = [0]
for s in sizes:
offsets.append(offsets[-1] + s)
for gen in range(max_generations):
gen_pool = ResultPool(capacity=population_size)
self._evaluate_parameters(
total=len(pop),
par_value_list=pop,
result_pool=gen_pool,
parallel=parallel,
epoch_str=f'{gen + 1}/{max_generations}',
leave_progress_bar=False,
)
for item, perf in zip(gen_pool.items, gen_pool.perfs):
self.result_pool.push(item=item, perf=perf)
self.result_pool.cut(keep_largest=maximize_target)
# 选择:按 perf 排序取前 select_top_ratio 作为父代
idx_sorted = np.argsort(gen_pool.perfs)
if maximize_target:
idx_sorted = idx_sorted[::-1]
n_parents = max(2, int(len(pop) * select_top_ratio))
parent_indices = idx_sorted[:n_parents]
parents = [gen_pool.items[i] for i in parent_indices]
# 交叉与变异生成下一代
offspring = []
while len(offspring) < population_size:
a, b = random.choice(parents), random.choice(parents)
vec_a = space.point_to_vector(a)
vec_b = space.point_to_vector(b)
child_vec = np.empty_like(vec_a)
for d in range(dim):
s, e = offsets[d], offsets[d + 1]
if random.random() < 0.5:
child_vec[s:e] = vec_a[s:e]
else:
child_vec[s:e] = vec_b[s:e]
child = space.vector_to_point(child_vec)
# 变异:每维以 mutation_rate 替换为该轴随机值
child_list = list(child)
for d in range(dim):
if random.random() < mutation_rate:
child_list[d] = list(space.axis[d].gen_values(1, 'rand'))[0]
child = tuple(child_list)
if child in space:
offspring.append(child)
pop = offspring[:population_size]
self.result_pool.cut(keep_largest=maximize_target)
def _search_gradient(self,
space: Space) -> None:
""" 最优参数搜索算法5:梯度下降法(多点同时梯度搜索)
在参数空间中寻找优化结果变优最快的方向,始终保持向最优方向前进(采用自适应步长)一直到结果不再改变或达到
最大步数为止。在参数空间中随机选择N个起点开始搜索,输出结果为最后一步的N个结果。
邻域通过 space.neighbors(point, axis_index, ...) 生成,支持 int/float/enum/int_array/float_array。
仅对 float 维做自适应步长(放大/缩小);无改进时缩小步长,步长过小或连续无改进达阈值则终止该轨迹。
Parameters
----------
space: Space
参数空间
Returns
-------
None
"""
start_count = self.search_config.get('start_count', 10)
max_steps = self.search_config.get('max_steps', 20)
maximize_target = self.search_config['maximize_target']
parallel = self.parallel
dim = space.dim
types = space.types
# 每维步长(仅 float 维使用,其余为 None)
def _init_step_sizes():
step_sizes = []
for d in range(dim):
ax = space.axis[d]
if types[d] == 'float':
sz = getattr(ax, 'size', None)
step_sizes.append(max(1e-9, (sz * 0.1)) if sz is not None else 0.1)
else:
step_sizes.append(None)
return step_sizes
# 生成 N 个起点
par_iter, total = space.extract(start_count, how='rand')
starts = list(par_iter)
if total == 0 or len(starts) == 0:
return
step_size_scale_up = 1.2
step_size_scale_down = 0.5
step_size_max_ratio = 0.5
step_size_min = 1e-9
no_improve_threshold = 3
tmp_pool = ResultPool(capacity=1000)
for start in starts:
x = start
step_sizes = _init_step_sizes()
no_improve_count = 0
current_perf = None
for _ in range(max_steps):
# 收集邻域候选:对每维调用 space.neighbors
candidates = []
for d in range(dim):
step_arg = step_sizes[d] if step_sizes[d] is not None else None
nb = space.neighbors(x, d, count=2, step=step_arg)
for c in nb:
if c in space:
candidates.append(c)
# 当前点 + 所有候选,一起评估
to_eval = [x] + candidates
tmp_pool.clear()
self._evaluate_parameters(
total=len(to_eval),
par_value_list=to_eval,
result_pool=tmp_pool,
parallel=parallel,
leave_progress_bar=False,
)
if not tmp_pool.items or len(tmp_pool.items) == 0:
break
perfs = list(tmp_pool.perfs)
current_perf = perfs[0]
if len(perfs) == 1:
no_improve_count += 1
for d in range(dim):
if step_sizes[d] is not None:
step_sizes[d] = max(step_size_min, step_sizes[d] * step_size_scale_down)
if no_improve_count >= no_improve_threshold:
break
continue
# 找最优候选(索引 0 为当前点,1 及以后为候选)
candidate_perfs = perfs[1:]
if maximize_target:
best_cand_idx = int(np.argmax(candidate_perfs))
best_cand_perf = candidate_perfs[best_cand_idx]
improved = best_cand_perf > current_perf
else:
best_cand_idx = int(np.argmin(candidate_perfs))
best_cand_perf = candidate_perfs[best_cand_idx]
improved = best_cand_perf < current_perf
if improved:
x = candidates[best_cand_idx]
current_perf = best_cand_perf
no_improve_count = 0
for d in range(dim):
if step_sizes[d] is not None:
ax = space.axis[d]
sz = getattr(ax, 'size', None)
cap = (sz * step_size_max_ratio) if sz is not None else step_sizes[d] * 2
step_sizes[d] = min(step_sizes[d] * step_size_scale_up, cap)
else:
no_improve_count += 1
for d in range(dim):
if step_sizes[d] is not None:
step_sizes[d] = max(step_size_min, step_sizes[d] * step_size_scale_down)
if no_improve_count >= no_improve_threshold:
break
all_too_small = all(
s is None or s <= step_size_min for s in step_sizes
)
if all_too_small:
break
# 轨迹终点 x 及其表现写入 result_pool(若未评估过则补评一次)
if current_perf is None:
tmp_pool.clear()
self._evaluate_parameters(
total=1,
par_value_list=[x],
result_pool=tmp_pool,
parallel=parallel,
leave_progress_bar=False,
)
if tmp_pool.items:
current_perf = tmp_pool.perfs[0]
if current_perf is not None:
self.result_pool.push(item=x, perf=current_perf)
self.result_pool.cut(keep_largest=maximize_target)
def _search_pso(self,
space: Space) -> None:
""" 最优参数搜索算法6: Particle Swarm Optimization 粒子群优化算法
在参数空间中随机选择N个起点作为粒子群的初始位置,每个粒子根据自身的历史最优位置和全局的历史最优位置
来调整自己的速度和位置,逐步向最优解靠近。经过多次迭代后,粒子群会收敛到全局最优解或近似最优解。
数值表示使用 space.point_to_vector / space.vector_to_point,在编码向量空间内做速度与位置更新,
再映射回合法参数点。惯性权重 w=0.7,个体系数 c1=1.5,社会系数 c2=1.5。
Parameters
----------
space: qt.Space
参数空间对象
Returns
-------
None,搜索的结果最佳值会被保存在self.result_pool属性中
"""
population_size = self.search_config['population_size']
max_iterations = self.search_config['max_iterations']
maximize_target = self.search_config['maximize_target']
parallel = self.parallel
# PSO 超参数(常量,暂不从 config 暴露)
w = 0.7
c1 = 1.5
c2 = 1.5
par_iter, total = space.extract(population_size, how='rand')
positions = list(par_iter)
if not positions:
return
# 编码向量长度与各轴跨度(用于速度初始化)
vec_len = space.point_to_vector(positions[0]).size
sizes = space.vector_axis_sizes
dim = space.dim
offsets = [0]
for s in sizes:
offsets.append(offsets[-1] + s)
span_per_elem = np.zeros(vec_len)
for d in range(dim):
ax = space.axis[d]
boe = space.boes[d]
s, e = offsets[d], offsets[d + 1]
if ax.par_type in ['int', 'float']:
span = float(ax.ubound - ax.lbound) or 1.0
span_per_elem[s:e] = span
elif ax.par_type == 'enum':
enum_list = list(boe) if isinstance(boe, tuple) else boe
span = float(max(1, len(enum_list) - 1))
span_per_elem[s:e] = span
else:
span = float(ax.ubound - ax.lbound) or 1.0
span_per_elem[s:e] = span
# 初始化速度:小范围随机,与各维跨度成比例
velocities = [
np.random.uniform(-0.1 * span_per_elem, 0.1 * span_per_elem)
for _ in range(len(positions))
]
# 评估初始位置,初始化 pbest 与 gbest
pbest_points = list(positions)
pbest_perfs = [None] * len(positions)
tmp_pool = ResultPool(capacity=len(positions))
self._evaluate_parameters(
total=len(positions),
par_value_list=positions,
result_pool=tmp_pool,
parallel=parallel,
epoch_str='1/1',
leave_progress_bar=False,
)
for i, (point, perf) in enumerate(zip(tmp_pool.items, tmp_pool.perfs)):
pbest_perfs[i] = perf
if maximize_target:
gbest_idx = max(range(len(pbest_perfs)), key=lambda j: pbest_perfs[j] if pbest_perfs[j] is not None else float('-inf'))
else:
gbest_idx = min(range(len(pbest_perfs)), key=lambda j: pbest_perfs[j] if pbest_perfs[j] is not None else float('inf'))
gbest_point = pbest_points[gbest_idx]
gbest_perf = pbest_perfs[gbest_idx]
for iteration in range(max_iterations - 1):
gbest_vec = space.point_to_vector(gbest_point)
for i in range(len(positions)):
x_vec = space.point_to_vector(positions[i])
pbest_vec = space.point_to_vector(pbest_points[i])
r1, r2 = np.random.random(), np.random.random()
v = velocities[i]
v = w * v + c1 * r1 * (pbest_vec - x_vec) + c2 * r2 * (gbest_vec - x_vec)
velocities[i] = v
x_new_vec = x_vec + v
new_point = space.vector_to_point(x_new_vec)
positions[i] = new_point
tmp_pool = ResultPool(capacity=len(positions))
self._evaluate_parameters(
total=len(positions),
par_value_list=positions,
result_pool=tmp_pool,
parallel=parallel,
epoch_str=f'{iteration + 2}/{max_iterations}',
leave_progress_bar=False,
)
for i, (point, perf) in enumerate(zip(tmp_pool.items, tmp_pool.perfs)):
if perf is None:
continue
better = (perf > pbest_perfs[i]) if maximize_target else (perf < pbest_perfs[i])
if pbest_perfs[i] is None or better:
pbest_perfs[i] = perf
pbest_points[i] = point
gbest_better = (perf > gbest_perf) if maximize_target else (perf < gbest_perf)
if gbest_perf is None or gbest_better:
gbest_perf = perf
gbest_point = point
for point, perf in zip(pbest_points, pbest_perfs):
if perf is not None:
self.result_pool.push(item=point, perf=perf)
self.result_pool.cut(keep_largest=maximize_target)
def _search_bayesian(self,
space: Space) -> None:
""" 最优参数搜索算法6: 贝叶斯优化算法
贝叶斯优化是一种基于贝叶斯统计理论的全局优化方法,适用于高维、非凸、黑箱函数的优化问题。
它通过构建目标函数的概率模型(通常是高斯过程)来指导参数搜索过程,从而在有限的评估次数内找到最优解。
流程:初始随机采样 -> 用 (X, y) 拟合 surrogate(RBF 核高斯过程)-> 迭代:在候选点上计算 UCB 采集函数,
选取采集值最大的点评估 -> 更新 (X, y) 与 result_pool,直至达到 max_iterations。
Parameters
----------
space: qt.Space
参数空间对象
Returns
-------
None,搜索的结果最佳值会被保存在self.result_pool属性中
"""
init_sample_count = self.search_config['init_sample_count']
max_iterations = self.search_config['max_iterations']
maximize_target = self.search_config['maximize_target']
parallel = self.parallel
# 采集函数超参数(UCB 的 kappa)
kappa = 2.0
# 每轮采集时的候选点数量
candidate_count = 200
# ----- 1. 初始随机采样 -----
par_iter, total = space.extract(init_sample_count, how='rand')
par_list = list(par_iter)
if not par_list:
return
init_pool = ResultPool(capacity=len(par_list) + max_iterations)
self._evaluate_parameters(
total=len(par_list),
par_value_list=par_list,
result_pool=init_pool,
parallel=parallel,
epoch_str='init/1',
leave_progress_bar=False,
)
# 编码为 (X, y);若为 minimize 则 y 取负,使 surrogate 端统一为“最大化”
X_list = [space.point_to_vector(p) for p in init_pool.items]
X = np.array(X_list)
y_raw = np.array(init_pool.perfs, dtype=float)
y = y_raw if maximize_target else -y_raw
for p, perf in zip(init_pool.items, init_pool.perfs):
self.result_pool.push(item=p, perf=perf)
self.result_pool.cut(keep_largest=maximize_target)
# ----- 2. 贝叶斯迭代 -----
for it in range(max_iterations - 1):
cand_iter, _ = space.extract(candidate_count, how='rand')
cand_points = list(cand_iter)
if not cand_points:
break
X_cand = np.array([space.point_to_vector(p) for p in cand_points])
mu, sigma = _gp_predict_rbf(X, y, X_cand, length_scale=None, noise=1e-5)
if mu is None:
next_point = cand_points[0]
else:
sigma = np.maximum(sigma, 1e-10)
ucb = mu + kappa * sigma
best_idx = int(np.argmax(ucb))
next_point = cand_points[best_idx]
# 评估建议点
perf = self._evaluate_parameter(next_point)
x_vec = space.point_to_vector(next_point)
X = np.vstack([X, x_vec.reshape(1, -1)])
y = np.append(y, perf if maximize_target else -perf)
self.result_pool.push(item=next_point, perf=perf)
self.result_pool.cut(keep_largest=maximize_target)
def report_result(self, stage: str) -> str:
""" 根据优化结果池生成优化结果报告字符串
Parameters
----------
stage: str
报告阶段,取值为 'optimization' 或 'validation',分别表示优化区间报告和验证区间报告
Returns
-------
report_string: str
优化结果报告字符串
"""
from qteasy.visual import opti_result_str
result = self.result_pool.extra if stage == 'optimization' else self.validated_pool.extra
report_string = opti_result_str(
result=result,
name='Validation report' if stage == 'validation' else 'Optimization report',
benchmark=self.benchmark,
opti_time=self.opti_time,
eval_time=self.eval_time,
)
return report_string
def plot_result(self) -> None:
""" 根据优化结果池生成优化结果图表
"""
from qteasy.visual import _plot_test_result
_plot_test_result(
plot_type=self.test_plot_type,
opti_eval_res=self.result_pool.extra,
test_eval_res=self.validated_pool.extra,
opti_duration=self.opti_time,
eval_duration=self.eval_time,
test_duration=self.test_time,
)
AVAILABLE_OPTIMIZERS = {
'grid': _search_grid,
'montecarlo': _search_montecarlo,
'SA': _search_sa,
'GA': _search_ga,
'gradient': _search_gradient,
'PSO': _search_pso,
'bayesian': _search_bayesian,
}