def compare_strategy_vs_benchmark(self, br, strategy_df, benchmark_df):
"""
compare_strategy_vs_benchmark - Compares the trading strategy we are backtesting against a benchmark
Parameters
----------
br : BacktestRequest
Parameters for backtest such as start and finish dates
strategy_df : pandas.DataFrame
Strategy time series
benchmark_df : pandas.DataFrame
Benchmark time series
"""
include_benchmark = False
calc_stats = False
if hasattr(br, 'include_benchmark'): include_benchmark = br.include_benchmark
if hasattr(br, 'calc_stats'): calc_stats = br.calc_stats
if include_benchmark:
tsd = TimeSeriesDesc()
cash_backtest = CashBacktest()
ts_filter = TimeSeriesFilter()
ts_calcs = TimeSeriesCalcs()
# align strategy time series with that of benchmark
strategy_df, benchmark_df = strategy_df.align(benchmark_df, join='left', axis = 0)
# if necessary apply vol target to benchmark (to make it comparable with strategy)
if hasattr(br, 'portfolio_vol_adjust'):
if br.portfolio_vol_adjust is True:
benchmark_df = cash_backtest.calculate_vol_adjusted_index_from_prices(benchmark_df, br = br)
# only calculate return statistics if this has been specified (note when different frequencies of data
# might underrepresent vol
if calc_stats:
benchmark_df = benchmark_df.fillna(method='ffill')
tsd.calculate_ret_stats_from_prices(benchmark_df, br.ann_factor)
benchmark_df.columns = tsd.summary()
# realign strategy & benchmark
strategy_benchmark_df = strategy_df.join(benchmark_df, how='inner')
strategy_benchmark_df = strategy_benchmark_df.fillna(method='ffill')
strategy_benchmark_df = ts_filter.filter_time_series_by_date(br.plot_start, br.finish_date, strategy_benchmark_df)
strategy_benchmark_df = ts_calcs.create_mult_index_from_prices(strategy_benchmark_df)
self._benchmark_pnl = benchmark_df
self._benchmark_tsd = tsd
return strategy_benchmark_df
return strategy_df
class CashBacktest:
def __init__(self):
self.logger = LoggerManager().getLogger(__name__)
self._pnl = None
self._portfolio = None
return
def calculate_trading_PnL(self, br, asset_a_df, signal_df):
"""
calculate_trading_PnL - Calculates P&L of a trading strategy and statistics to be retrieved later
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
signal_df : pandas.DataFrame
Signals for the trading strategy
"""
tsc = TimeSeriesCalcs()
# signal_df.to_csv('e:/temp0.csv')
# make sure the dates of both traded asset and signal are aligned properly
asset_df, signal_df = asset_a_df.align(signal_df, join='left', axis = 'index')
# only allow signals to change on the days when we can trade assets
signal_df = signal_df.mask(numpy.isnan(asset_df.values)) # fill asset holidays with NaN signals
signal_df = signal_df.fillna(method='ffill') # fill these down
asset_df = asset_df.fillna(method='ffill') # fill down asset holidays
returns_df = tsc.calculate_returns(asset_df)
tc = br.spot_tc_bp
signal_cols = signal_df.columns.values
returns_cols = returns_df.columns.values
pnl_cols = []
for i in range(0, len(returns_cols)):
pnl_cols.append(returns_cols[i] + " / " + signal_cols[i])
# do we have a vol target for individual signals?
if hasattr(br, 'signal_vol_adjust'):
if br.signal_vol_adjust is True:
if not(hasattr(br, 'signal_vol_resample_type')):
br.signal_vol_resample_type = 'mean'
leverage_df = self.calculate_leverage_factor(returns_df, br.signal_vol_target, br.signal_vol_max_leverage,
br.signal_vol_periods, br.signal_vol_obs_in_year,
br.signal_vol_rebalance_freq, br.signal_vol_resample_freq,
br.signal_vol_resample_type)
signal_df = pandas.DataFrame(
signal_df.values * leverage_df.values, index = signal_df.index, columns = signal_df.columns)
self._individual_leverage = leverage_df # contains leverage of individual signal (before portfolio vol target)
_pnl = tsc.calculate_signal_returns_with_tc_matrix(signal_df, returns_df, tc = tc)
_pnl.columns = pnl_cols
# portfolio is average of the underlying signals: should we sum them or average them?
if hasattr(br, 'portfolio_combination'):
if br.portfolio_combination == 'sum':
portfolio = pandas.DataFrame(data = _pnl.sum(axis = 1), index = _pnl.index, columns = ['Portfolio'])
elif br.portfolio_combination == 'mean':
portfolio = pandas.DataFrame(data = _pnl.mean(axis = 1), index = _pnl.index, columns = ['Portfolio'])
else:
portfolio = pandas.DataFrame(data = _pnl.mean(axis = 1), index = _pnl.index, columns = ['Portfolio'])
portfolio_leverage_df = pandas.DataFrame(data = numpy.ones(len(_pnl.index)), index = _pnl.index, columns = ['Portfolio'])
# should we apply vol target on a portfolio level basis?
if hasattr(br, 'portfolio_vol_adjust'):
if br.portfolio_vol_adjust is True:
portfolio, portfolio_leverage_df = self.calculate_vol_adjusted_returns(portfolio, br = br)
self._portfolio = portfolio
self._signal = signal_df # individual signals (before portfolio leverage)
self._portfolio_leverage = portfolio_leverage_df # leverage on portfolio
# multiply portfolio leverage * individual signals to get final position signals
length_cols = len(signal_df.columns)
leverage_matrix = numpy.repeat(portfolio_leverage_df.values.flatten()[numpy.newaxis,:], length_cols, 0)
# final portfolio signals (including signal & portfolio leverage)
self._portfolio_signal = pandas.DataFrame(
data = numpy.multiply(numpy.transpose(leverage_matrix), signal_df.values),
index = signal_df.index, columns = signal_df.columns)
if hasattr(br, 'portfolio_combination'):
if br.portfolio_combination == 'sum':
pass
elif br.portfolio_combination == 'mean':
self._portfolio_signal = self._portfolio_signal / float(length_cols)
else:
self._portfolio_signal = self._portfolio_signal / float(length_cols)
self._pnl = _pnl # individual signals P&L
# TODO FIX very slow - hence only calculate on demand
_pnl_trades = None
# _pnl_trades = tsc.calculate_individual_trade_gains(signal_df, _pnl)
self._pnl_trades = _pnl_trades
self._tsd_pnl = TimeSeriesDesc()
self._tsd_pnl.calculate_ret_stats(self._pnl, br.ann_factor)
self._portfolio.columns = ['Port']
self._tsd_portfolio = TimeSeriesDesc()
self._tsd_portfolio.calculate_ret_stats(self._portfolio, br.ann_factor)
self._cumpnl = tsc.create_mult_index(self._pnl) # individual signals cumulative P&L
self._cumpnl.columns = pnl_cols
self._cumportfolio = tsc.create_mult_index(self._portfolio) # portfolio cumulative P&L
self._cumportfolio.columns = ['Port']
def calculate_vol_adjusted_index_from_prices(self, prices_df, br):
"""
calculate_vol_adjusted_index_from_price - Adjusts an index of prices for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
Returns
-------
pandas.Dataframe containing vol adjusted index
"""
tsc = TimeSeriesCalcs()
returns_df, leverage_df = self.calculate_vol_adjusted_returns(prices_df, br, returns = False)
return tsc.create_mult_index(returns_df)
def calculate_vol_adjusted_returns(self, returns_df, br, returns = True):
"""
calculate_vol_adjusted_returns - Adjusts returns for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
returns_a_df : pandas.DataFrame
Asset returns to be traded
Returns
-------
pandas.DataFrame
"""
tsc = TimeSeriesCalcs()
if not returns: returns_df = tsc.calculate_returns(returns_df)
if not(hasattr(br, 'portfolio_vol_resample_type')):
br.portfolio_vol_resample_type = 'mean'
leverage_df = self.calculate_leverage_factor(returns_df,
br.portfolio_vol_target, br.portfolio_vol_max_leverage,
br.portfolio_vol_periods, br.portfolio_vol_obs_in_year,
br.portfolio_vol_rebalance_freq, br.portfolio_vol_resample_freq,
br.portfolio_vol_resample_type)
vol_returns_df = tsc.calculate_signal_returns_with_tc_matrix(leverage_df, returns_df, tc = br.spot_tc_bp)
vol_returns_df.columns = returns_df.columns
return vol_returns_df, leverage_df
def calculate_leverage_factor(self, returns_df, vol_target, vol_max_leverage, vol_periods = 60, vol_obs_in_year = 252,
vol_rebalance_freq = 'BM', data_resample_freq = None, data_resample_type = 'mean',
returns = True, period_shift = 0):
"""
calculate_leverage_factor - Calculates the time series of leverage for a specified vol target
Parameters
----------
returns_df : DataFrame
Asset returns
vol_target : float
vol target for assets
vol_max_leverage : float
maximum leverage allowed
vol_periods : int
number of periods to calculate volatility
vol_obs_in_year : int
number of observations in the year
vol_rebalance_freq : str
how often to rebalance
vol_resample_freq : str
do we need to resample the underlying data first? (eg. have we got intraday data?)
returns : boolean
is this returns time series or prices?
period_shift : int
should we delay the signal by a number of periods?
Returns
-------
pandas.Dataframe
"""
tsc = TimeSeriesCalcs()
if data_resample_freq is not None:
return
# TODO not implemented yet
if not returns: returns_df = tsc.calculate_returns(returns_df)
roll_vol_df = tsc.rolling_volatility(returns_df,
periods = vol_periods, obs_in_year = vol_obs_in_year).shift(period_shift)
# calculate the leverage as function of vol target (with max lev constraint)
lev_df = vol_target / roll_vol_df
lev_df[lev_df > vol_max_leverage] = vol_max_leverage
# should we take the mean, first, last in our resample
if data_resample_type == 'mean':
lev_df = lev_df.resample(vol_rebalance_freq).mean()
elif data_resample_type == 'first':
lev_df = lev_df.resample(vol_rebalance_freq).first()
elif data_resample_type == 'last':
lev_df = lev_df.resample(vol_rebalance_freq).last()
else:
# TODO implement other types
return
returns_df, lev_df = returns_df.align(lev_df, join='left', axis = 0)
lev_df = lev_df.fillna(method='ffill')
lev_df.ix[0:vol_periods] = numpy.nan # ignore the first elements before the vol window kicks in
return lev_df
def get_backtest_output(self):
return
def get_pnl(self):
"""
get_pnl - Gets P&L returns
Returns
-------
pandas.Dataframe
"""
return self._pnl
def get_pnl_trades(self):
"""
get_pnl_trades - Gets P&L of each individual trade per signal
Returns
-------
pandas.Dataframe
"""
if self._pnl_trades is None:
tsc = TimeSeriesCalcs()
self._pnl_trades = tsc.calculate_individual_trade_gains(self._signal, self._pnl)
return self._pnl_trades
def get_pnl_desc(self):
"""
get_pnl_desc - Gets P&L return statistics in a string format
Returns
-------
str
"""
return self._tsd_signals.summary()
def get_pnl_tsd(self):
"""
get_pnl_tsd - Gets P&L return statistics of individual strategies as class to be queried
Returns
-------
TimeSeriesDesc
"""
return self._tsd_pnl
def get_cumpnl(self):
"""
get_cumpnl - Gets P&L as a cumulative time series of individual assets
Returns
-------
pandas.DataFrame
"""
return self._cumpnl
def get_cumportfolio(self):
"""
get_cumportfolio - Gets P&L as a cumulative time series of portfolio
Returns
-------
pandas.DataFrame
"""
return self._cumportfolio
def get_portfolio_pnl(self):
"""
get_portfolio_pnl - Gets portfolio returns in raw form (ie. not indexed into cumulative form)
Returns
-------
pandas.DataFrame
"""
return self._portfolio
def get_portfolio_pnl_desc(self):
"""
get_portfolio_pnl_desc - Gets P&L return statistics of portfolio as string
Returns
-------
pandas.DataFrame
"""
return self._tsd_portfolio.summary()
def get_portfolio_pnl_tsd(self):
"""
get_portfolio_pnl_tsd - Gets P&L return statistics of portfolio as class to be queried
Returns
-------
TimeSeriesDesc
"""
return self._tsd_portfolio
def get_individual_leverage(self):
"""
get_individual_leverage - Gets leverage for each asset historically
Returns
-------
pandas.DataFrame
"""
return self._individual_leverage
def get_porfolio_leverage(self):
"""
get_portfolio_leverage - Gets the leverage for the portfolio
Returns
-------
pandas.DataFrame
"""
return self._portfolio_leverage
def get_porfolio_signal(self):
"""
get_portfolio_signal - Gets the signals (with individual leverage & portfolio leverage) for each asset, which
equates to what we would trade in practice
Returns
-------
DataFrame
"""
return self._portfolio_signal
def get_signal(self):
"""
get_signal - Gets the signals (with individual leverage, but excluding portfolio leverage) for each asset
Returns
-------
pandas.DataFrame
"""
return self._signal
class CashBacktest:
def __init__(self):
self.logger = LoggerManager().getLogger(__name__)
self._pnl = None
self._portfolio = None
return
def calculate_trading_PnL(self, br, asset_a_df, signal_df):
"""
calculate_trading_PnL - Calculates P&L of a trading strategy and statistics to be retrieved later
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
signal_df : pandas.DataFrame
Signals for the trading strategy
"""
tsc = TimeSeriesCalcs()
# signal_df.to_csv('e:/temp0.csv')
# make sure the dates of both traded asset and signal are aligned properly
asset_df, signal_df = asset_a_df.align(signal_df,
join='left',
axis='index')
# only allow signals to change on the days when we can trade assets
signal_df = signal_df.mask(numpy.isnan(
asset_df.values)) # fill asset holidays with NaN signals
signal_df = signal_df.fillna(method='ffill') # fill these down
asset_df = asset_df.fillna(method='ffill') # fill down asset holidays
returns_df = tsc.calculate_returns(asset_df)
tc = br.spot_tc_bp
signal_cols = signal_df.columns.values
returns_cols = returns_df.columns.values
pnl_cols = []
for i in range(0, len(returns_cols)):
pnl_cols.append(returns_cols[i] + " / " + signal_cols[i])
# do we have a vol target for individual signals?
if hasattr(br, 'signal_vol_adjust'):
if br.signal_vol_adjust is True:
if not (hasattr(br, 'signal_vol_resample_type')):
br.signal_vol_resample_type = 'mean'
leverage_df = self.calculate_leverage_factor(
returns_df, br.signal_vol_target,
br.signal_vol_max_leverage, br.signal_vol_periods,
br.signal_vol_obs_in_year, br.signal_vol_rebalance_freq,
br.signal_vol_resample_freq, br.signal_vol_resample_type)
signal_df = pandas.DataFrame(signal_df.values *
leverage_df.values,
index=signal_df.index,
columns=signal_df.columns)
self._individual_leverage = leverage_df # contains leverage of individual signal (before portfolio vol target)
_pnl = tsc.calculate_signal_returns_with_tc_matrix(signal_df,
returns_df,
tc=tc)
_pnl.columns = pnl_cols
# portfolio is average of the underlying signals: should we sum them or average them?
if hasattr(br, 'portfolio_combination'):
if br.portfolio_combination == 'sum':
portfolio = pandas.DataFrame(data=_pnl.sum(axis=1),
index=_pnl.index,
columns=['Portfolio'])
elif br.portfolio_combination == 'mean':
portfolio = pandas.DataFrame(data=_pnl.mean(axis=1),
index=_pnl.index,
columns=['Portfolio'])
else:
portfolio = pandas.DataFrame(data=_pnl.mean(axis=1),
index=_pnl.index,
columns=['Portfolio'])
portfolio_leverage_df = pandas.DataFrame(data=numpy.ones(
len(_pnl.index)),
index=_pnl.index,
columns=['Portfolio'])
# should we apply vol target on a portfolio level basis?
if hasattr(br, 'portfolio_vol_adjust'):
if br.portfolio_vol_adjust is True:
portfolio, portfolio_leverage_df = self.calculate_vol_adjusted_returns(
portfolio, br=br)
self._portfolio = portfolio
self._signal = signal_df # individual signals (before portfolio leverage)
self._portfolio_leverage = portfolio_leverage_df # leverage on portfolio
# multiply portfolio leverage * individual signals to get final position signals
length_cols = len(signal_df.columns)
leverage_matrix = numpy.repeat(
portfolio_leverage_df.values.flatten()[numpy.newaxis, :],
length_cols, 0)
# final portfolio signals (including signal & portfolio leverage)
self._portfolio_signal = pandas.DataFrame(data=numpy.multiply(
numpy.transpose(leverage_matrix), signal_df.values),
index=signal_df.index,
columns=signal_df.columns)
if hasattr(br, 'portfolio_combination'):
if br.portfolio_combination == 'sum':
pass
elif br.portfolio_combination == 'mean':
self._portfolio_signal = self._portfolio_signal / float(
length_cols)
else:
self._portfolio_signal = self._portfolio_signal / float(
length_cols)
self._pnl = _pnl # individual signals P&L
# TODO FIX very slow - hence only calculate on demand
_pnl_trades = None
# _pnl_trades = tsc.calculate_individual_trade_gains(signal_df, _pnl)
self._pnl_trades = _pnl_trades
self._tsd_pnl = TimeSeriesDesc()
self._tsd_pnl.calculate_ret_stats(self._pnl, br.ann_factor)
self._portfolio.columns = ['Port']
self._tsd_portfolio = TimeSeriesDesc()
self._tsd_portfolio.calculate_ret_stats(self._portfolio, br.ann_factor)
self._cumpnl = tsc.create_mult_index(
self._pnl) # individual signals cumulative P&L
self._cumpnl.columns = pnl_cols
self._cumportfolio = tsc.create_mult_index(
self._portfolio) # portfolio cumulative P&L
self._cumportfolio.columns = ['Port']
def calculate_vol_adjusted_index_from_prices(self, prices_df, br):
"""
calculate_vol_adjusted_index_from_price - Adjusts an index of prices for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
Returns
-------
pandas.Dataframe containing vol adjusted index
"""
tsc = TimeSeriesCalcs()
returns_df, leverage_df = self.calculate_vol_adjusted_returns(
prices_df, br, returns=False)
return tsc.create_mult_index(returns_df)
def calculate_vol_adjusted_returns(self, returns_df, br, returns=True):
"""
calculate_vol_adjusted_returns - Adjusts returns for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
returns_a_df : pandas.DataFrame
Asset returns to be traded
Returns
-------
pandas.DataFrame
"""
tsc = TimeSeriesCalcs()
if not returns: returns_df = tsc.calculate_returns(returns_df)
if not (hasattr(br, 'portfolio_vol_resample_type')):
br.portfolio_vol_resample_type = 'mean'
leverage_df = self.calculate_leverage_factor(
returns_df, br.portfolio_vol_target, br.portfolio_vol_max_leverage,
br.portfolio_vol_periods, br.portfolio_vol_obs_in_year,
br.portfolio_vol_rebalance_freq, br.portfolio_vol_resample_freq,
br.portfolio_vol_resample_type)
vol_returns_df = tsc.calculate_signal_returns_with_tc_matrix(
leverage_df, returns_df, tc=br.spot_tc_bp)
vol_returns_df.columns = returns_df.columns
return vol_returns_df, leverage_df
def calculate_leverage_factor(self,
returns_df,
vol_target,
vol_max_leverage,
vol_periods=60,
vol_obs_in_year=252,
vol_rebalance_freq='BM',
data_resample_freq=None,
data_resample_type='mean',
returns=True,
period_shift=0):
"""
calculate_leverage_factor - Calculates the time series of leverage for a specified vol target
Parameters
----------
returns_df : DataFrame
Asset returns
vol_target : float
vol target for assets
vol_max_leverage : float
maximum leverage allowed
vol_periods : int
number of periods to calculate volatility
vol_obs_in_year : int
number of observations in the year
vol_rebalance_freq : str
how often to rebalance
vol_resample_freq : str
do we need to resample the underlying data first? (eg. have we got intraday data?)
returns : boolean
is this returns time series or prices?
period_shift : int
should we delay the signal by a number of periods?
Returns
-------
pandas.Dataframe
"""
tsc = TimeSeriesCalcs()
if data_resample_freq is not None:
return
# TODO not implemented yet
if not returns: returns_df = tsc.calculate_returns(returns_df)
roll_vol_df = tsc.rolling_volatility(
returns_df, periods=vol_periods,
obs_in_year=vol_obs_in_year).shift(period_shift)
# calculate the leverage as function of vol target (with max lev constraint)
lev_df = vol_target / roll_vol_df
lev_df[lev_df > vol_max_leverage] = vol_max_leverage
# should we take the mean, first, last in our resample
if data_resample_type == 'mean':
lev_df = lev_df.resample(vol_rebalance_freq).mean()
elif data_resample_type == 'first':
lev_df = lev_df.resample(vol_rebalance_freq).first()
elif data_resample_type == 'last':
lev_df = lev_df.resample(vol_rebalance_freq).last()
else:
# TODO implement other types
return
returns_df, lev_df = returns_df.align(lev_df, join='left', axis=0)
lev_df = lev_df.fillna(method='ffill')
lev_df.ix[
0:
vol_periods] = numpy.nan # ignore the first elements before the vol window kicks in
return lev_df
def get_backtest_output(self):
return
def get_pnl(self):
"""
get_pnl - Gets P&L returns
Returns
-------
pandas.Dataframe
"""
return self._pnl
def get_pnl_trades(self):
"""
get_pnl_trades - Gets P&L of each individual trade per signal
Returns
-------
pandas.Dataframe
"""
if self._pnl_trades is None:
tsc = TimeSeriesCalcs()
self._pnl_trades = tsc.calculate_individual_trade_gains(
self._signal, self._pnl)
return self._pnl_trades
def get_pnl_desc(self):
"""
get_pnl_desc - Gets P&L return statistics in a string format
Returns
-------
str
"""
return self._tsd_signals.summary()
def get_pnl_tsd(self):
"""
get_pnl_tsd - Gets P&L return statistics of individual strategies as class to be queried
Returns
-------
TimeSeriesDesc
"""
return self._tsd_pnl
def get_cumpnl(self):
"""
get_cumpnl - Gets P&L as a cumulative time series of individual assets
Returns
-------
pandas.DataFrame
"""
return self._cumpnl
def get_cumportfolio(self):
"""
get_cumportfolio - Gets P&L as a cumulative time series of portfolio
Returns
-------
pandas.DataFrame
"""
return self._cumportfolio
def get_portfolio_pnl(self):
"""
get_portfolio_pnl - Gets portfolio returns in raw form (ie. not indexed into cumulative form)
Returns
-------
pandas.DataFrame
"""
return self._portfolio
def get_portfolio_pnl_desc(self):
"""
get_portfolio_pnl_desc - Gets P&L return statistics of portfolio as string
Returns
-------
pandas.DataFrame
"""
return self._tsd_portfolio.summary()
def get_portfolio_pnl_tsd(self):
"""
get_portfolio_pnl_tsd - Gets P&L return statistics of portfolio as class to be queried
Returns
-------
TimeSeriesDesc
"""
return self._tsd_portfolio
def get_individual_leverage(self):
"""
get_individual_leverage - Gets leverage for each asset historically
Returns
-------
pandas.DataFrame
"""
return self._individual_leverage
def get_porfolio_leverage(self):
"""
get_portfolio_leverage - Gets the leverage for the portfolio
Returns
-------
pandas.DataFrame
"""
return self._portfolio_leverage
def get_porfolio_signal(self):
"""
get_portfolio_signal - Gets the signals (with individual leverage & portfolio leverage) for each asset, which
equates to what we would trade in practice
Returns
-------
DataFrame
"""
return self._portfolio_signal
def get_signal(self):
"""
get_signal - Gets the signals (with individual leverage, but excluding portfolio leverage) for each asset
Returns
-------
pandas.DataFrame
"""
return self._signal
class CashBacktest:
def __init__(self):
self.logger = LoggerManager().getLogger(__name__)
self._pnl = None
self._portfolio = None
return
def calculate_trading_PnL(self, br, asset_a_df, signal_df):
"""
calculate_trading_PnL - Calculates P&L of a trading strategy and statistics to be retrieved later
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
signal_df : pandas.DataFrame
Signals for the trading strategy
"""
tsc = TimeSeriesCalcs()
# make sure the dates of both traded asset and signal are aligned properly
asset_df, signal_df = asset_a_df.align(signal_df, join='left', axis = 0)
# only allow signals to change on the days when we can trade assets
signal_df = signal_df.mask(numpy.isnan(asset_df.values)) # fill asset holidays with NaN signals
signal_df = signal_df.fillna(method='ffill') # fill these down
asset_df = asset_df.fillna(method='ffill') # fill down asset holidays
returns_df = tsc.calculate_returns(asset_df)
tc = br.spot_tc_bp
signal_cols = signal_df.columns.values
returns_cols = returns_df.columns.values
pnl_cols = []
for i in range(0, len(returns_cols)):
pnl_cols.append(returns_cols[i] + " / " + signal_cols[i])
if hasattr(br, 'signal_vol_adjust'):
if br.signal_vol_adjust is True:
leverage_df = self.calculate_leverage_factor(returns_df, br.signal_vol_target, br.signal_vol_max_leverage,
br.signal_vol_periods, br.signal_vol_obs_in_year,
br.signal_vol_rebalance_freq)
signal_df = pandas.DataFrame(
signal_df.values * leverage_df.values, index = signal_df.index, columns = signal_df.columns)
self._individual_leverage = leverage_df
_pnl = tsc.calculate_signal_returns_with_tc_matrix(signal_df, returns_df, tc = tc)
_pnl.columns = pnl_cols
# portfolio is average of the underlying signals
interim_portfolio = pandas.DataFrame(data = _pnl.mean(axis = 1), index = _pnl.index, columns = ['Portfolio'])
portfolio_leverage_df = pandas.DataFrame(data = numpy.ones(len(_pnl.index)), index = _pnl.index, columns = ['Portfolio'])
if hasattr(br, 'portfolio_vol_adjust'):
if br.portfolio_vol_adjust is True:
interim_portfolio, portfolio_leverage_df = self.calculate_vol_adjusted_returns(interim_portfolio, br = br)
self._portfolio = interim_portfolio
self._signal = signal_df
self._portfolio_leverage = portfolio_leverage_df
# multiply portfolio leverage * individual signals to get final position signals
length_cols = len(signal_df.columns)
leverage_matrix = numpy.repeat(portfolio_leverage_df.values.flatten()[numpy.newaxis,:], length_cols, 0)
self._portfolio_signal = pandas.DataFrame(
data = numpy.multiply(numpy.transpose(leverage_matrix), signal_df.values),
index = signal_df.index, columns = signal_df.columns) / float(length_cols)
self._pnl = _pnl
self._tsd_pnl = TimeSeriesDesc()
self._tsd_pnl.calculate_ret_stats(self._pnl, br.ann_factor)
self._portfolio.columns = ['Port']
self._tsd_portfolio = TimeSeriesDesc()
self._tsd_portfolio.calculate_ret_stats(self._portfolio, br.ann_factor)
self._cumpnl = tsc.create_mult_index(self._pnl)
self._cumpnl.columns = pnl_cols
self._cumportfolio = tsc.create_mult_index(self._portfolio)
self._cumportfolio.columns = ['Port']
def calculate_vol_adjusted_index_from_prices(self, prices_df, br):
"""
calculate_vol_adjusted_index_from_price - Adjusts an index of prices for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
asset_a_df : pandas.DataFrame
Asset prices to be traded
Returns
-------
pandas.Dataframe containing vol adjusted index
"""
tsc = TimeSeriesCalcs()
returns_df, leverage_df = self.calculate_vol_adjusted_returns(prices_df, br, returns = False)
return tsc.create_mult_index(returns_df)
def calculate_vol_adjusted_returns(self, returns_df, br, returns = True):
"""
calculate_vol_adjusted_returns - Adjusts returns for a vol target
Parameters
----------
br : BacktestRequest
Parameters for the backtest specifying start date, finish data, transaction costs etc.
returns_a_df : pandas.DataFrame
Asset returns to be traded
Returns
-------
pandas.DataFrame
"""
tsc = TimeSeriesCalcs()
if not returns: returns_df = tsc.calculate_returns(returns_df)
leverage_df = self.calculate_leverage_factor(returns_df,
br.portfolio_vol_target, br.portfolio_vol_max_leverage,
br.portfolio_vol_periods, br.portfolio_vol_obs_in_year,
br.portfolio_vol_rebalance_freq)
vol_returns_df = tsc.calculate_signal_returns_with_tc_matrix(leverage_df, returns_df, tc = br.spot_tc_bp)
vol_returns_df.columns = returns_df.columns
return vol_returns_df, leverage_df
def calculate_leverage_factor(self, returns_df, vol_target, vol_max_leverage, vol_periods = 60, vol_obs_in_year = 252,
vol_rebalance_freq = 'BM', returns = True, period_shift = 0):
"""
calculate_leverage_factor - Calculates the time series of leverage for a specified vol target
Parameters
----------
returns_df : DataFrame
Asset returns
vol_target : float
vol target for assets
vol_max_leverage : float
maximum leverage allowed
vol_periods : int
number of periods to calculate volatility
vol_obs_in_year : int
number of observations in the year
vol_rebalance_freq : str
how often to rebalance
returns : boolean
is this returns time series or prices?
period_shift : int
should we delay the signal by a number of periods?
Returns
-------
pandas.Dataframe
"""
tsc = TimeSeriesCalcs()
if not returns: returns_df = tsc.calculate_returns(returns_df)
roll_vol_df = tsc.rolling_volatility(returns_df,
periods = vol_periods, obs_in_year = vol_obs_in_year).shift(period_shift)
# calculate the leverage as function of vol target (with max lev constraint)
lev_df = vol_target / roll_vol_df
lev_df[lev_df > vol_max_leverage] = vol_max_leverage
# only allow the leverage change at resampling frequency (eg. monthly 'BM')
lev_df = lev_df.resample(vol_rebalance_freq)
returns_df, lev_df = returns_df.align(lev_df, join='left', axis = 0)
lev_df = lev_df.fillna(method='ffill')
return lev_df
def get_backtest_output(self):
return
def get_pnl(self):
"""
get_pnl - Gets P&L returns
Returns
-------
pandas.Dataframe
"""
return self._pnl
def get_pnl_desc(self):
"""
get_pnl_desc - Gets P&L return statistics in a string format
Returns
-------
str
"""
return self._tsd_signals.summary()
def get_pnl_tsd(self):
"""
get_pnl_tsd - Gets P&L return statistics class which can be queried.
Returns
-------
TimeSeriesDesc
"""
return self._tsd_pnl
def get_cumpnl(self):
"""
get_cumpnl - Gets P&L as a cumulative time series of individual assets
Returns
-------
pandas.DataFrame
"""
return self._cumpnl
def get_cumportfolio(self):
"""
get_cumportfolio - Gets P&L as a cumulative time series of portfolio
Returns
-------
pandas.DataFrame
"""
return self._cumportfolio
def get_portfolio_pnl_desc(self):
"""
get_portfolio_pnl_desc - Gets P&L return statistics of portfolio as string
Returns
-------
pandas.DataFrame
"""
return self._tsd_portfolio.summary()
def get_portfolio_pnl_tsd(self):
"""
get_portfolio_pnl_tsd - Gets P&L return statistics of portfolio as class to be queried
Returns
-------
TimeSeriesDesc
"""
return self._tsd_portfolio
def get_individual_leverage(self):
"""
get_individual_leverage - Gets leverage for each asset historically
Returns
-------
pandas.DataFrame
"""
return self._individual_leverage
def get_porfolio_leverage(self):
"""
get_portfolio_leverage - Gets the leverage for the portfolio
Returns
-------
pandas.DataFrame
"""
return self._portfolio_leverage
def get_porfolio_signal(self):
"""
get_portfolio_signal - Gets the signals (with individual leverage & portfolio leverage) for each asset, which
equates to what we would trade in practice
Returns
-------
DataFrame
"""
return self._portfolio_signal
def get_signal(self):
"""
get_signal - Gets the signals (with individual leverage, but excluding portfolio leverage) for each asset
Returns
-------
pandas.DataFrame
"""
return self._signal