Files
catalyst/zipline/finance/performance/tracker.py
T
Andrew Liang 98f3fc9326 MAINT: Refactor application of capital changes
Previously, on the dt of a capital change, we use the un-updated
prices to find the ending performance of the previous subperiod and
then got the new prices to determine the portfolio value used to
calculate the delta, without actually updating the performance
before applying the capital change. This logic is confusing and
unintuitive. Instead, save the ending performance as we do previously,
but have temp values for the starting current subperiod value.
Update those temp values after processing the capital change
2016-08-01 11:51:45 -04:00

477 lines
18 KiB
Python

#
# Copyright 2016 Quantopian, Inc.
#
# 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.
"""
Performance Tracking
====================
+-----------------+----------------------------------------------------+
| key | value |
+=================+====================================================+
| period_start | The beginning of the period to be tracked. datetime|
| | in pytz.utc timezone. Will always be 0:00 on the |
| | date in UTC. The fact that the time may be on the |
| | prior day in the exchange's local time is ignored |
+-----------------+----------------------------------------------------+
| period_end | The end of the period to be tracked. datetime |
| | in pytz.utc timezone. Will always be 23:59 on the |
| | date in UTC. The fact that the time may be on the |
| | next day in the exchange's local time is ignored |
+-----------------+----------------------------------------------------+
| progress | percentage of test completed |
+-----------------+----------------------------------------------------+
| capital_base | The initial capital assumed for this tracker. |
+-----------------+----------------------------------------------------+
| cumulative_perf | A dictionary representing the cumulative |
| | performance through all the events delivered to |
| | this tracker. For details see the comments on |
| | :py:meth:`PerformancePeriod.to_dict` |
+-----------------+----------------------------------------------------+
| todays_perf | A dictionary representing the cumulative |
| | performance through all the events delivered to |
| | this tracker with datetime stamps between last_open|
| | and last_close. For details see the comments on |
| | :py:meth:`PerformancePeriod.to_dict` |
| | TODO: adding this because we calculate it. May be |
| | overkill. |
+-----------------+----------------------------------------------------+
| cumulative_risk | A dictionary representing the risk metrics |
| _metrics | calculated based on the positions aggregated |
| | through all the events delivered to this tracker. |
| | For details look at the comments for |
| | :py:meth:`zipline.finance.risk.RiskMetrics.to_dict`|
+-----------------+----------------------------------------------------+
"""
from __future__ import division
import logbook
import pandas as pd
from pandas.tseries.tools import normalize_date
from zipline.finance.performance.period import PerformancePeriod
from zipline.errors import NoFurtherDataError
import zipline.finance.risk as risk
from . position_tracker import PositionTracker
log = logbook.Logger('Performance')
class PerformanceTracker(object):
"""
Tracks the performance of the algorithm.
"""
def __init__(self, sim_params, trading_calendar, env):
self.sim_params = sim_params
self.trading_calendar = trading_calendar
self.asset_finder = env.asset_finder
self.treasury_curves = env.treasury_curves
self.period_start = self.sim_params.start_session
self.period_end = self.sim_params.end_session
self.last_close = self.sim_params.last_close
self._current_session = self.sim_params.start_session
self.market_open, self.market_close = \
self.trading_calendar.open_and_close_for_session(
self._current_session
)
self.total_session_count = len(self.sim_params.sessions)
self.capital_base = self.sim_params.capital_base
self.emission_rate = sim_params.emission_rate
self.position_tracker = PositionTracker(
asset_finder=env.asset_finder,
data_frequency=self.sim_params.data_frequency
)
if self.emission_rate == 'daily':
self.all_benchmark_returns = pd.Series(
index=self.sim_params.sessions
)
self.cumulative_risk_metrics = \
risk.RiskMetricsCumulative(
self.sim_params,
self.treasury_curves,
self.trading_calendar
)
elif self.emission_rate == 'minute':
self.all_benchmark_returns = pd.Series(index=pd.date_range(
self.sim_params.first_open, self.sim_params.last_close,
freq='Min')
)
self.cumulative_risk_metrics = \
risk.RiskMetricsCumulative(
self.sim_params,
self.treasury_curves,
self.trading_calendar,
create_first_day_stats=True
)
# this performance period will span the entire simulation from
# inception.
self.cumulative_performance = PerformancePeriod(
# initial cash is your capital base.
starting_cash=self.capital_base,
data_frequency=self.sim_params.data_frequency,
# the cumulative period will be calculated over the entire test.
period_open=self.period_start,
period_close=self.period_end,
# don't save the transactions for the cumulative
# period
keep_transactions=False,
keep_orders=False,
# don't serialize positions for cumulative period
serialize_positions=False,
asset_finder=self.asset_finder,
name="Cumulative"
)
self.cumulative_performance.position_tracker = self.position_tracker
# this performance period will span just the current market day
self.todays_performance = PerformancePeriod(
# initial cash is your capital base.
starting_cash=self.capital_base,
data_frequency=self.sim_params.data_frequency,
# the daily period will be calculated for the market day
period_open=self.market_open,
period_close=self.market_close,
keep_transactions=True,
keep_orders=True,
serialize_positions=True,
asset_finder=self.asset_finder,
name="Daily"
)
self.todays_performance.position_tracker = self.position_tracker
self.saved_dt = self.period_start
# one indexed so that we reach 100%
self.session_count = 0.0
self.txn_count = 0
self.account_needs_update = True
self._account = None
def __repr__(self):
return "%s(%r)" % (
self.__class__.__name__,
{'simulation parameters': self.sim_params})
@property
def progress(self):
if self.emission_rate == 'minute':
# Fake a value
return 1.0
elif self.emission_rate == 'daily':
return self.session_count / self.total_session_count
def set_date(self, date):
if self.emission_rate == 'minute':
self.saved_dt = date
self.todays_performance.period_close = self.saved_dt
def get_portfolio(self, performance_needs_update):
if performance_needs_update:
self.update_performance()
self.account_needs_update = True
return self.cumulative_performance.as_portfolio()
def update_performance(self):
# calculate performance as of last trade
self.cumulative_performance.calculate_performance()
self.todays_performance.calculate_performance()
def get_account(self, performance_needs_update):
if performance_needs_update:
self.update_performance()
self.account_needs_update = True
if self.account_needs_update:
self._update_account()
return self._account
def _update_account(self):
self._account = self.cumulative_performance.as_account()
self.account_needs_update = False
def to_dict(self, emission_type=None):
"""
Creates a dictionary representing the state of this tracker.
Returns a dict object of the form described in header comments.
"""
# Default to the emission rate of this tracker if no type is provided
if emission_type is None:
emission_type = self.emission_rate
_dict = {
'period_start': self.period_start,
'period_end': self.period_end,
'capital_base': self.capital_base,
'cumulative_perf': self.cumulative_performance.to_dict(),
'progress': self.progress,
'cumulative_risk_metrics': self.cumulative_risk_metrics.to_dict()
}
if emission_type == 'daily':
_dict['daily_perf'] = self.todays_performance.to_dict()
elif emission_type == 'minute':
_dict['minute_perf'] = self.todays_performance.to_dict(
self.saved_dt)
else:
raise ValueError("Invalid emission type: %s" % emission_type)
return _dict
def prepare_capital_change(self, is_interday):
self.cumulative_performance.initialize_subperiod_divider()
if not is_interday:
# Change comes in the middle of day
self.todays_performance.initialize_subperiod_divider()
def process_capital_change(self, capital_change_amount, is_interday):
self.cumulative_performance.set_current_subperiod_starting_values(
capital_change_amount)
if is_interday:
# Change comes between days
self.todays_performance.adjust_period_starting_capital(
capital_change_amount)
else:
# Change comes in the middle of day
self.todays_performance.set_current_subperiod_starting_values(
capital_change_amount)
def process_transaction(self, transaction):
self.txn_count += 1
self.cumulative_performance.handle_execution(transaction)
self.todays_performance.handle_execution(transaction)
self.position_tracker.execute_transaction(transaction)
def handle_splits(self, splits):
leftover_cash = self.position_tracker.handle_splits(splits)
if leftover_cash > 0:
self.cumulative_performance.handle_cash_payment(leftover_cash)
self.todays_performance.handle_cash_payment(leftover_cash)
def process_order(self, event):
self.cumulative_performance.record_order(event)
self.todays_performance.record_order(event)
def process_commission(self, commission):
sid = commission['sid']
cost = commission['cost']
self.position_tracker.handle_commission(sid, cost)
self.cumulative_performance.handle_commission(cost)
self.todays_performance.handle_commission(cost)
def process_close_position(self, asset, dt, data_portal):
txn = self.position_tracker.\
maybe_create_close_position_transaction(asset, dt, data_portal)
if txn:
self.process_transaction(txn)
def check_upcoming_dividends(self, next_session, adjustment_reader):
"""
Check if we currently own any stocks with dividends whose ex_date is
the next trading day. Track how much we should be payed on those
dividends' pay dates.
Then check if we are owed cash/stock for any dividends whose pay date
is the next trading day. Apply all such benefits, then recalculate
performance.
"""
if adjustment_reader is None:
return
position_tracker = self.position_tracker
held_sids = set(position_tracker.positions)
# Dividends whose ex_date is the next trading day. We need to check if
# we own any of these stocks so we know to pay them out when the pay
# date comes.
if held_sids:
cash_dividends = adjustment_reader.get_dividends_with_ex_date(
held_sids,
next_session,
self.asset_finder
)
stock_dividends = adjustment_reader.\
get_stock_dividends_with_ex_date(
held_sids,
next_session,
self.asset_finder
)
position_tracker.earn_dividends(
cash_dividends,
stock_dividends
)
net_cash_payment = position_tracker.pay_dividends(next_session)
if not net_cash_payment:
return
self.cumulative_performance.handle_dividends_paid(net_cash_payment)
self.todays_performance.handle_dividends_paid(net_cash_payment)
def handle_minute_close(self, dt, data_portal):
"""
Handles the close of the given minute in minute emission.
Parameters
__________
dt : Timestamp
The minute that is ending
Returns
_______
A minute perf packet.
"""
self.position_tracker.sync_last_sale_prices(dt, False, data_portal)
self.update_performance()
todays_date = normalize_date(dt)
account = self.get_account(False)
bench_returns = self.all_benchmark_returns.loc[todays_date:dt]
# cumulative returns
bench_since_open = (1. + bench_returns).prod() - 1
self.cumulative_risk_metrics.update(todays_date,
self.todays_performance.returns,
bench_since_open,
account.leverage)
minute_packet = self.to_dict(emission_type='minute')
return minute_packet
def handle_market_close(self, dt, data_portal):
"""
Handles the close of the given day, in both minute and daily emission.
In daily emission, also updates performance, benchmark and risk metrics
as it would in handle_minute_close if it were minute emission.
Parameters
__________
dt : Timestamp
The minute that is ending
Returns
_______
A daily perf packet.
"""
completed_session = self._current_session
if self.emission_rate == 'daily':
# this method is called for both minutely and daily emissions, but
# this chunk of code here only applies for daily emissions. (since
# it's done every minute, elsewhere, for minutely emission).
self.position_tracker.sync_last_sale_prices(dt, False, data_portal)
self.update_performance()
account = self.get_account(False)
benchmark_value = self.all_benchmark_returns[completed_session]
self.cumulative_risk_metrics.update(
completed_session,
self.todays_performance.returns,
benchmark_value,
account.leverage)
# increment the day counter before we move markers forward.
self.session_count += 1.0
# Get the next trading day and, if it is past the bounds of this
# simulation, return the daily perf packet
try:
next_session = self.trading_calendar.next_session_label(
completed_session
)
except NoFurtherDataError:
next_session = None
# Take a snapshot of our current performance to return to the
# browser.
daily_update = self.to_dict(emission_type='daily')
# On the last day of the test, don't create tomorrow's performance
# period. We may not be able to find the next trading day if we're at
# the end of our historical data
if self.market_close >= self.last_close:
return daily_update
# If the next trading day is irrelevant, then return the daily packet
if (next_session is None) or (next_session >= self.last_close):
return daily_update
# move the market day markers forward
# TODO Is this redundant with next_trading_day above?
self._current_session = next_session
self.market_open, self.market_close = \
self.trading_calendar.open_and_close_for_session(
self._current_session
)
# Roll over positions to current day.
self.todays_performance.rollover()
self.todays_performance.period_open = self.market_open
self.todays_performance.period_close = self.market_close
# Check for any dividends, then return the daily perf packet
self.check_upcoming_dividends(
next_session=next_session,
adjustment_reader=data_portal._adjustment_reader
)
return daily_update
def handle_simulation_end(self):
"""
When the simulation is complete, run the full period risk report
and send it out on the results socket.
"""
log_msg = "Simulated {n} trading days out of {m}."
log.info(log_msg.format(n=int(self.session_count),
m=self.total_session_count))
log.info("first open: {d}".format(
d=self.sim_params.first_open))
log.info("last close: {d}".format(
d=self.sim_params.last_close))
bms = pd.Series(
index=self.cumulative_risk_metrics.cont_index,
data=self.cumulative_risk_metrics.benchmark_returns_cont)
ars = pd.Series(
index=self.cumulative_risk_metrics.cont_index,
data=self.cumulative_risk_metrics.algorithm_returns_cont)
acl = self.cumulative_risk_metrics.algorithm_cumulative_leverages
self.risk_report = risk.RiskReport(
ars,
self.sim_params,
benchmark_returns=bms,
algorithm_leverages=acl,
trading_calendar=self.trading_calendar,
treasury_curves=self.treasury_curves,
)
risk_dict = self.risk_report.to_dict()
return risk_dict