ENH: Actually use rolling windows for EWMA in MACD

This commit is contained in:
Ana Ruelas
2016-11-14 16:35:56 -05:00
parent 7f762d02bf
commit 10f5cc2cbb
3 changed files with 141 additions and 39 deletions
+77
View File
@@ -5,6 +5,7 @@ from six.moves import range
import numpy as np
import pandas as pd
import talib
from numpy.random import random_integers
from zipline.lib.adjusted_array import AdjustedArray
from zipline.pipeline.data import USEquityPricing
@@ -16,6 +17,7 @@ from zipline.pipeline.factors import (
LinearWeightedMovingAverage,
RateOfChangePercentage,
TrueRange,
MovingAverageConvergenceDivergence
)
from zipline.testing import parameter_space
from zipline.testing.fixtures import ZiplineTestCase
@@ -403,3 +405,78 @@ class TestTrueRange(ZiplineTestCase):
tr.compute(today, assets, out, highs, lows, closes)
assert_equal(out, np.full((3,), 2.))
class MovingAverageConvergenceDivergenceCase(ZiplineTestCase):
def test_MACD_window_length_generation(self):
signal_period = random_integers(1, 90)
fast_period = random_integers(signal_period+1, signal_period+100)
slow_period = random_integers(fast_period+1, fast_period+100)
ewma = MovingAverageConvergenceDivergence(
fast_period=fast_period,
slow_period=slow_period,
signal_period=signal_period,
)
assert_equal(
ewma.window_length,
slow_period+signal_period-1,
)
def test_moving_average_convergence_divergence(self):
fast_period = 3
slow_period = 8
signal_period = 2
macd = MovingAverageConvergenceDivergence(
fast_period=fast_period,
slow_period=slow_period,
signal_period=signal_period,
)
today = pd.Timestamp('2016', tz='utc')
nassets = macd.window_length
assets = pd.Index(np.arange(nassets))
days_col = np.arange(start=-.05,
stop=.01*nassets-.05,
step=.01)[:, np.newaxis]
close = np.logspace(start=.01, stop=.10, num=nassets) - 1 + days_col
dtype = [
('macd', 'f8'),
('signal', 'f8'),
('hist', 'f8'),
]
out = np.recarray(
shape=(nassets,),
dtype=dtype,
buf=np.empty(shape=(nassets,), dtype=dtype),
)
macd.compute(
today,
assets,
out,
close,
fast_period,
slow_period,
signal_period,
)
expected_macd = np.array([0.01691553] * nassets)
expected_signal = np.array([0.01691553] * nassets)
expected_hist = np.array([0] * nassets)
np.testing.assert_almost_equal(
out.macd,
expected_macd,
decimal=8
)
np.testing.assert_almost_equal(
out.signal,
expected_signal,
decimal=8
)
np.testing.assert_almost_equal(
out.hist,
expected_hist,
decimal=8
)
+6
View File
@@ -32,6 +32,9 @@ from .technical import (
TrueRange,
VWAP,
WeightedAverageValue,
MovingAverageConvergenceDivergence,
MACD,
AnnualizedVolatility,
)
__all__ = [
@@ -62,4 +65,7 @@ __all__ = [
'TrueRange',
'VWAP',
'WeightedAverageValue',
'MovingAverageConvergenceDivergence',
'MACD',
'AnnualizedVolatility',
]
+58 -39
View File
@@ -21,7 +21,6 @@ from numpy import (
NINF,
sqrt,
sum as np_sum,
nan
)
from numexpr import evaluate
@@ -38,10 +37,9 @@ from zipline.utils.math_utils import (
nansum,
nanmin,
)
from zipline.utils.numpy_utils import rolling_window
from .factor import CustomFactor
from talib import MACD
class Returns(CustomFactor):
"""
@@ -448,11 +446,6 @@ class ExponentialWeightedMovingStdDev(_ExponentialWeightedFactor):
out[:] = sqrt(variance * bias_correction)
# Convenience aliases.
EWMA = ExponentialWeightedMovingAverage
EWMSTD = ExponentialWeightedMovingStdDev
class BollingerBands(CustomFactor):
"""
Bollinger Bands technical indicator.
@@ -688,8 +681,7 @@ class TrueRange(CustomFactor):
)
class MovingAverageConvergenceDivergence(CustomFactor):
class MovingAverageConvergenceDivergence(_ExponentialWeightedFactor):
"""
Moving Average Convergence/Divergence (MACD)
https://en.wikipedia.org/wiki/MACD
@@ -700,21 +692,22 @@ class MovingAverageConvergenceDivergence(CustomFactor):
trend in a stock's price.
**Default Inputs:** :data:`zipline.pipeline.data.USEquityPricing.close`
**Default Window Length:** None
**Default Window Length:** Window length is automatically calculated as the
sum of slow_period and signal_period.
Parameters
----------
fast_period : int >= 0, <= window_length
The window length for the "fast" EMA.
The window length for the "fast" EWMA. Default is 12.
slow_period : int >= 0, <= window_length
The window length for the "slow" EMA.
The window length for the "slow" EWMA. Default is 26.
signal_period' : int >= 0, <= slow_period
The window length for the signal line.
The window length for the signal line. Default is 9.
Returns
-------
MACD: The difference between "fast" EMA and "slow" EMA.
signal: The signal_period length period EMA of the MACD line.
MACD: The difference between "fast" EWMA and "slow" EWMA.
signal: The EWMA of the MACD line using `signal_period` as span.
hist: Difference between MACD and signal. (Divergence series)
"""
inputs = [USEquityPricing.close]
@@ -728,47 +721,73 @@ class MovingAverageConvergenceDivergence(CustomFactor):
*args,
**kwargs):
return super(MovingAverageConvergenceDivergence, cls).__new__(
cls,
fast_period=fast_period,
slow_period=slow_period,
signal_period=signal_period,
window_length=slow_period + signal_period,
window_length=slow_period + signal_period - 1,
*args, **kwargs
)
def calculate_macd(self, col, fast, slow, signal):
try:
macd, sig, hist = MACD(col,
fastperiod=fast,
slowperiod=slow,
signalperiod=signal)
return macd[-1], sig[-1], hist[-1]
except:
return nan, nan, nan
def calculate_ewma(self, data, length):
decay_rate = 1.0 - (2.0 / (1.0 + length))
return average(data,
axis=1,
weights=self.weights(length, decay_rate))
def calculate_macd(self, col):
slow_EWMA = self.calculate_ewma(
rolling_window(
col,
self.params['slow_period']
),
self.params['slow_period'])
fast_EWMA = self.calculate_ewma(
rolling_window(
col,
self.params['fast_period']
)[-self.params['signal_period']:],
self.params['fast_period'])
macd = fast_EWMA - slow_EWMA
signal_line = self.calculate_ewma(
macd.reshape(-1, self.params['signal_period']),
self.params['signal_period'])
hist = macd[-1] - signal_line
return macd[-1], signal_line[-1], hist[-1]
def compute(self, today, assets, out, close, fast_period, slow_period,
signal_period):
n = len(close)
macd, sig, hist = zip(*map(self.calculate_macd,
close.T,
[fast_period]*n,
[slow_period]*n,
[signal_period]*n))
out.MACD[:] = macd
macd, sig, hist = zip(*map(self.calculate_macd, close.T))
out.macd[:] = macd
out.signal[:] = sig
out.hist[:] = hist
class AnnualVolatility(CustomFactor):
class AnnualizedVolatility(CustomFactor):
"""
Volatility
https://en.wikipedia.org/wiki/Volatility_(finance)
The degree of variation of a series over time as measured by the standard
deviation of the data over the course of a year.
deviation of returns.
**Default Inputs:** :data:`zipline.pipeline.data.USEquityPricing.close`
**Default Inputs:**
:data:`zipline.pipeline.factors.Returns(window_length=2)`
Parameters
----------
annualization_factor :
The number of time units per year. Defaults to average number of NYSE
trading days per year, 252.
"""
inputs = [USEquityPricing.close]
inputs = [Returns(window_length=2)]
params = {'annualization_factor': 252}
window_length = 252
def compute(self, today, assets, out, closes):
out[:] = nanstd(closes, ddof=1, axis=0) * (252 ** 0.5)
def compute(self, today, assets, out, returns, annualization_factor):
out[:] = nanstd(returns, ddof=0, axis=0) * (annualization_factor ** .5)
# Convenience aliases.
EWMA = ExponentialWeightedMovingAverage
EWMSTD = ExponentialWeightedMovingStdDev
MACD = MovingAverageConvergenceDivergence