Merge pull request #1603 from quantopian/randc-built-in-factors-twekas

Randc built in factors twekas
This commit is contained in:
Scott Sanderson
2016-11-28 15:30:40 -05:00
committed by GitHub
3 changed files with 136 additions and 59 deletions
+69 -18
View File
@@ -5,7 +5,7 @@ from six.moves import range
import numpy as np
import pandas as pd
import talib
from numpy.random import random_integers
from numpy.random import RandomState
from zipline.lib.adjusted_array import AdjustedArray
from zipline.pipeline.data import USEquityPricing
@@ -421,10 +421,13 @@ class MovingAverageConvergenceDivergenceTestCase(ZiplineTestCase):
.mean()
.values[-1])
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)
@parameter_space(seed=range(5))
def test_MACD_window_length_generation(self, seed):
rng = RandomState(seed)
signal_period = rng.randint(1, 90)
fast_period = rng.randint(signal_period + 1, signal_period + 100)
slow_period = rng.randint(fast_period + 1, fast_period + 100)
ewma = MovingAverageConvergenceDivergenceSignal(
fast_period=fast_period,
slow_period=slow_period,
@@ -432,14 +435,53 @@ class MovingAverageConvergenceDivergenceTestCase(ZiplineTestCase):
)
assert_equal(
ewma.window_length,
slow_period+signal_period-1,
slow_period + signal_period - 1,
)
def test_moving_average_convergence_divergence(self):
def test_bad_inputs(self):
template = (
"MACDSignal() expected a value greater than or equal to 1"
" for argument %r, but got 0 instead."
)
with self.assertRaises(ValueError) as e:
MovingAverageConvergenceDivergenceSignal(fast_period=0)
self.assertEqual(template % 'fast_period', str(e.exception))
with self.assertRaises(ValueError) as e:
MovingAverageConvergenceDivergenceSignal(slow_period=0)
self.assertEqual(template % 'slow_period', str(e.exception))
with self.assertRaises(ValueError) as e:
MovingAverageConvergenceDivergenceSignal(signal_period=0)
self.assertEqual(template % 'signal_period', str(e.exception))
with self.assertRaises(ValueError) as e:
MovingAverageConvergenceDivergenceSignal(
fast_period=5,
slow_period=4,
)
expected = (
"'slow_period' must be greater than 'fast_period', but got\n"
"slow_period=4, fast_period=5"
)
self.assertEqual(expected, str(e.exception))
@parameter_space(
seed=range(2),
fast_period=[3, 5],
slow_period=[8, 10],
signal_period=[3, 9],
__fail_fast=True,
)
def test_moving_average_convergence_divergence(self,
seed,
fast_period,
slow_period,
signal_period):
rng = RandomState(seed)
nassets = 3
fast_period = 3
slow_period = 8
signal_period = 2
macd = MovingAverageConvergenceDivergenceSignal(
fast_period=fast_period,
@@ -450,7 +492,7 @@ class MovingAverageConvergenceDivergenceTestCase(ZiplineTestCase):
today = pd.Timestamp('2016', tz='utc')
assets = pd.Index(np.arange(nassets))
out = np.empty(shape=(nassets,), dtype=np.float64)
close = np.random.rand(macd.window_length, nassets)
close = rng.rand(macd.window_length, nassets)
macd.compute(
today,
@@ -465,14 +507,23 @@ class MovingAverageConvergenceDivergenceTestCase(ZiplineTestCase):
close_df = pd.DataFrame(close)
fast_ewma = self.expected_ewma(
close_df,
fast_period)
fast_period,
)
slow_ewma = self.expected_ewma(
close_df,
slow_period)
expected_signal = self.expected_ewma(
fast_ewma-slow_ewma,
slow_period,
)
signal_ewma = self.expected_ewma(
fast_ewma - slow_ewma,
signal_period
).values[-1]
)
# Everything but the last row should be NaN.
self.assertTrue(signal_ewma.iloc[:-1].isnull().all().all())
# We're testing a single compute call, which we expect to be equivalent
# to the last row of the frame we calculated with pandas.
expected_signal = signal_ewma.values[-1]
np.testing.assert_almost_equal(
out,
@@ -492,7 +543,7 @@ class AnnualizedVolatilityTestCase(ZiplineTestCase):
nassets = 3
ann_vol = AnnualizedVolatility()
today = pd.Timestamp('2016', tz='utc')
assets = np.arange(nassets, dtype=np.float)
assets = np.arange(nassets, dtype=np.float64)
returns = np.full((ann_vol.window_length, nassets),
0.004,
dtype=np.float64)
@@ -514,7 +565,7 @@ class AnnualizedVolatilityTestCase(ZiplineTestCase):
nassets = 3
ann_vol = AnnualizedVolatility()
today = pd.Timestamp('2016', tz='utc')
assets = np.arange(nassets, dtype=np.float)
assets = np.arange(nassets, dtype=np.float64)
returns = np.random.normal(loc=0.001,
scale=0.01,
size=(ann_vol.window_length, nassets))
+66 -32
View File
@@ -14,6 +14,7 @@ from numpy import (
dstack,
exp,
fmax,
full,
inf,
isnan,
log,
@@ -25,8 +26,7 @@ from numexpr import evaluate
from zipline.pipeline.data import USEquityPricing
from zipline.pipeline.mixins import SingleInputMixin
from zipline.utils.numpy_utils import ignore_nanwarnings
from zipline.utils.input_validation import expect_types
from zipline.utils.input_validation import expect_bounded, expect_types
from zipline.utils.math_utils import (
nanargmax,
nanargmin,
@@ -35,9 +35,12 @@ from zipline.utils.math_utils import (
nanstd,
nansum,
nanmin,
exponential_weights,
)
from zipline.utils.numpy_utils import rolling_window
from zipline.utils.numpy_utils import (
float64_dtype,
ignore_nanwarnings,
rolling_window,
)
from .factor import CustomFactor
@@ -161,6 +164,28 @@ class AverageDollarVolume(CustomFactor):
out[:] = nansum(close * volume, axis=0) / len(close)
def exponential_weights(length, decay_rate):
"""
Build a weight vector for an exponentially-weighted statistic.
The resulting ndarray is of the form::
[decay_rate ** length, ..., decay_rate ** 2, decay_rate]
Parameters
----------
length : int
The length of the desired weight vector.
decay_rate : float
The rate at which entries in the weight vector increase or decrease.
Returns
-------
weights : ndarray[float64]
"""
return full(length, decay_rate, float64_dtype) ** arange(length + 1, 1, -1)
class _ExponentialWeightedFactor(SingleInputMixin, CustomFactor):
"""
Base class for factors implementing exponential-weighted operations.
@@ -379,13 +404,13 @@ class LinearWeightedMovingAverage(CustomFactor, SingleInputMixin):
ctx = ignore_nanwarnings()
def compute(self, today, assets, out, data):
num_days = data.shape[0]
ndays = data.shape[0]
# Initialize weights array
weights = arange(1, num_days + 1, dtype=float).reshape(num_days, 1)
weights = arange(1, ndays + 1, dtype=float64_dtype).reshape(ndays, 1)
# Compute normalizer
normalizer = (num_days * (num_days + 1)) / 2
normalizer = (ndays * (ndays + 1)) / 2
# Weight the data
weighted_data = data * weights
@@ -684,27 +709,34 @@ class MovingAverageConvergenceDivergenceSignal(CustomFactor):
trend in a stock's price.
**Default Inputs:** :data:`zipline.pipeline.data.USEquityPricing.close`
**Default Window Length:** Window length is automatically calculated as the
sum of slow_period and signal_period.
Parameters
----------
fast_period : int > 0
fast_period : int > 0, optional
The window length for the "fast" EWMA. Default is 12.
slow_period : int > 0, > fast_period
slow_period : int > 0, > fast_period, optional
The window length for the "slow" EWMA. Default is 26.
signal_period' : int > 0, < fast_period
signal_period' : int > 0, < fast_period, optional
The window length for the signal line. Default is 9.
Returns
-------
The EWMA of the difference between "fast" EWMA and "slow" EWMA line using
`signal_period` as span.
Notes
-----
Unlike most pipeline expressions, this factor does not accept a
``window_length`` parameter. ``window_length`` is inferred from
``slow_period`` and ``signal_period``.
"""
inputs = [USEquityPricing.close]
inputs = (USEquityPricing.close,)
# We don't use the default form of `params` here because we want to
# dynamically calculate `window_length` from the period lengths in our
# __new__.
params = ('fast_period', 'slow_period', 'signal_period')
@expect_bounded(
__funcname='MACDSignal',
fast_period=(1, None), # These must all be >= 1.
slow_period=(1, None),
signal_period=(1, None),
)
def __new__(cls,
fast_period=12,
slow_period=26,
@@ -712,12 +744,13 @@ class MovingAverageConvergenceDivergenceSignal(CustomFactor):
*args,
**kwargs):
if signal_period <= 0:
raise ValueError("'signal_period' must be larger than 0.")
if slow_period <= fast_period or fast_period <= signal_period:
if slow_period <= fast_period:
raise ValueError(
"'slow_period' must be larger than 'fast_period'."
"'fast_period' must be larger than 'signal_period'."
"'slow_period' must be greater than 'fast_period', but got\n"
"slow_period={slow}, fast_period={fast}".format(
slow=slow_period,
fast=fast_period,
)
)
return super(MovingAverageConvergenceDivergenceSignal, cls).__new__(
@@ -731,10 +764,11 @@ class MovingAverageConvergenceDivergenceSignal(CustomFactor):
def _ewma(self, data, length):
decay_rate = 1.0 - (2.0 / (1.0 + length))
return average(data,
axis=1,
weights=exponential_weights(length, decay_rate)
)
return average(
data,
axis=1,
weights=exponential_weights(length, decay_rate)
)
def compute(self, today, assets, out, close, fast_period, slow_period,
signal_period):
@@ -756,19 +790,19 @@ class AnnualizedVolatility(CustomFactor):
https://en.wikipedia.org/wiki/Volatility_(finance)
The degree of variation of a series over time as measured by the standard
deviation of returns.
deviation of daily returns.
**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.
annualization_factor : float, optional
The number of time units per year. Defaults is 252, the number of NYSE
trading days in a normal year.
"""
inputs = [Returns(window_length=2)]
params = {'annualization_factor': 252}
params = {'annualization_factor': 252.0}
window_length = 252
def compute(self, today, assets, out, returns, annualization_factor):
+1 -9
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@@ -14,7 +14,7 @@
# limitations under the License.
import math
from numpy import isnan, full, arange
from numpy import isnan
def tolerant_equals(a, b, atol=10e-7, rtol=10e-7, equal_nan=False):
@@ -77,11 +77,3 @@ def round_if_near_integer(a, epsilon=1e-4):
return round(a)
else:
return a
def exponential_weights(length, decay_rate):
"""
Return weighting vector for an exponential moving statistic on `length`
rows with a decay rate of `decay_rate`.
"""
return full(length, decay_rate, float) ** arange(length + 1, 1, -1)