# Copyright 2019 The TensorTrade Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License
import numpy as np
from typing import Union
from gym.spaces import Discrete
from tensortrade.actions import ActionStrategy, TradeActionUnion, DTypeString
from tensortrade.trades import Trade, TradeType
[docs]class DiscreteActionStrategy(ActionStrategy):
"""Simple discrete strategy, which calculates the trade amount as a fraction of the total balance."""
[docs] def __init__(self, n_actions: int = 20, instrument_symbol: str = 'BTC', max_allowed_slippage_percent: float = 1.0):
"""
Arguments:
n_actions: The number of bins to divide the total balance by. Defaults to 20 (i.e. 1/20, 2/20, ..., 20/20).
instrument_symbol: The exchange symbol of the instrument being traded. Defaults to 'BTC'.
max_allowed_slippage: The maximum amount above the current price the strategy will pay for an instrument. Defaults to 1.0 (i.e. 1%).
"""
super().__init__(action_space=Discrete(n_actions), dtype=np.int64)
self.n_actions = n_actions
self.instrument_symbol = instrument_symbol
self.max_allowed_slippage_percent = max_allowed_slippage_percent
@property
def dtype(self) -> DTypeString:
"""A type or str corresponding to the dtype of the `action_space`."""
return self._dtype
@dtype.setter
def dtype(self, dtype: DTypeString):
raise ValueError(
'Cannot change the dtype of a `SimpleDiscreteStrategy` due to the requirements of `gym.spaces.Discrete` spaces. ')
[docs] def get_trade(self, action: TradeActionUnion) -> Trade:
"""The trade type is determined by `action % len(TradeType)`, and the trade amount is determined by the multiplicity of the action.
For example, 1 = LIMIT_BUY|0.25, 2 = MARKET_BUY|0.25, 6 = LIMIT_BUY|0.5, 7 = MARKET_BUY|0.5, etc.
"""
n_splits = self.n_actions / len(TradeType)
trade_type = TradeType(action % len(TradeType))
trade_amount = int(action / len(TradeType)) * float(1 / n_splits) + (1 / n_splits)
current_price = self._exchange.current_price(symbol=self.instrument_symbol)
base_precision = self._exchange.base_precision
instrument_precision = self._exchange.instrument_precision
amount = self._exchange.instrument_balance(self.instrument_symbol)
price = current_price
if trade_type is TradeType.MARKET_BUY or trade_type is TradeType.LIMIT_BUY:
price_adjustment = 1 + (self.max_allowed_slippage_percent / 100)
price = max(round(current_price * price_adjustment, base_precision), base_precision)
amount = round(self._exchange.balance * 0.99 *
trade_amount / price, instrument_precision)
elif trade_type is TradeType.MARKET_SELL or trade_type is TradeType.LIMIT_SELL:
price_adjustment = 1 - (self.max_allowed_slippage_percent / 100)
price = round(current_price * price_adjustment, base_precision)
amount_held = self._exchange.portfolio.get(self.instrument_symbol, 0)
amount = round(amount_held * trade_amount, instrument_precision)
return Trade(self.instrument_symbol, trade_type, amount, price)