def test_regression_method_bad_type(self):
"""
Make sure we cannot call the Factor linear regression method on factors
or slices that are not of float or int dtype.
"""
# These are arbitrary for the purpose of this test.
returns_length = 2
regression_length = 10
returns = Returns(window_length=returns_length, inputs=[self.col])
returns_slice = returns[self.my_asset]
class BadTypeFactor(CustomFactor):
window_length = 1
inputs = []
dtype = datetime64ns_dtype
window_safe = True
def compute(self, today, assets, out):
pass
bad_type_factor = BadTypeFactor()
bad_type_factor_slice = bad_type_factor[self.my_asset]
with self.assertRaises(TypeError):
bad_type_factor.linear_regression(
target=returns_slice, regression_length=regression_length,
)
with self.assertRaises(TypeError):
returns.linear_regression(
target=bad_type_factor_slice,
regression_length=regression_length,
)
def test_factor_correlation_methods(self,
returns_length,
correlation_length):
"""
Ensure that `Factor.pearsonr` and `Factor.spearmanr` are consistent
with the built-in factors `RollingPearsonOfReturns` and
`RollingSpearmanOfReturns`.
"""
my_asset = self.my_asset
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
run_pipeline = self.run_pipeline
returns = Returns(window_length=returns_length, inputs=[self.col])
returns_slice = returns[my_asset]
pearson = returns.pearsonr(
target=returns_slice, correlation_length=correlation_length,
)
spearman = returns.spearmanr(
target=returns_slice, correlation_length=correlation_length,
)
expected_pearson = RollingPearsonOfReturns(
target=my_asset,
returns_length=returns_length,
correlation_length=correlation_length,
)
expected_spearman = RollingSpearmanOfReturns(
target=my_asset,
returns_length=returns_length,
correlation_length=correlation_length,
)
# These built-ins construct their own Returns factor to use as inputs,
# so the only way to set our own inputs is to do so after the fact.
# This should not be done in practice. It is necessary here because we
# want Returns to use our random data as an input, but by default it is
# using USEquityPricing.close.
expected_pearson.inputs = [returns, returns_slice]
expected_spearman.inputs = [returns, returns_slice]
columns = {
'pearson': pearson,
'spearman': spearman,
'expected_pearson': expected_pearson,
'expected_spearman': expected_spearman,
}
results = run_pipeline(Pipeline(columns=columns), start_date, end_date)
pearson_results = results['pearson'].unstack()
spearman_results = results['spearman'].unstack()
expected_pearson_results = results['expected_pearson'].unstack()
expected_spearman_results = results['expected_spearman'].unstack()
assert_frame_equal(pearson_results, expected_pearson_results)
assert_frame_equal(spearman_results, expected_spearman_results)
def test_slice(self, my_asset_column, window_length_):
"""
Test that slices can be created by indexing into a term, and that they
have the correct shape when used as inputs.
"""
sids = self.sids
my_asset = self.asset_finder.retrieve_asset(self.sids[my_asset_column])
returns = Returns(window_length=2, inputs=[self.col])
returns_slice = returns[my_asset]
class UsesSlicedInput(CustomFactor):
window_length = window_length_
inputs = [returns, returns_slice]
def compute(self, today, assets, out, returns, returns_slice):
# Make sure that our slice is the correct shape (i.e. has only
# one column) and that it has the same values as the original
# returns factor from which it is derived.
assert returns_slice.shape == (self.window_length, 1)
assert returns.shape == (self.window_length, len(sids))
check_arrays(returns_slice[:, 0], returns[:, my_asset_column])
# Assertions about the expected slice data are made in the `compute`
# function of our custom factor above.
self.run_pipeline(
Pipeline(columns={'uses_sliced_input': UsesSlicedInput()}),
self.pipeline_start_date,
self.pipeline_end_date,
)
def test_returns(self, seed_value, window_length):
returns = Returns(window_length=window_length)
today = datetime64(1, 'ns')
assets = arange(3)
out = empty((3, ), dtype=float)
seed(seed_value) # Seed so we get deterministic results.
test_data = abs(randn(window_length, 3))
# Calculate the expected returns
expected = (test_data[-1] - test_data[0]) / test_data[0]
out = empty((3, ), dtype=float)
returns.compute(today, assets, out, test_data)
check_allclose(expected, out)
def test_factor_regression_method(self, returns_length, regression_length):
"""
Ensure that `Factor.linear_regression` is consistent with the built-in
factor `RollingLinearRegressionOfReturns`.
"""
my_asset = self.my_asset
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
run_pipeline = self.run_pipeline
returns = Returns(window_length=returns_length, inputs=[self.col])
returns_slice = returns[my_asset]
regression = returns.linear_regression(
target=returns_slice, regression_length=regression_length,
)
expected_regression = RollingLinearRegressionOfReturns(
target=my_asset,
returns_length=returns_length,
regression_length=regression_length,
)
# This built-in constructs its own Returns factor to use as an input,
# so the only way to set our own input is to do so after the fact. This
# should not be done in practice. It is necessary here because we want
# Returns to use our random data as an input, but by default it is
# using USEquityPricing.close.
expected_regression.inputs = [returns, returns_slice]
columns = {
'regression': regression,
'expected_regression': expected_regression,
}
results = run_pipeline(Pipeline(columns=columns), start_date, end_date)
regression_results = results['regression'].unstack()
expected_regression_results = results['expected_regression'].unstack()
assert_frame_equal(regression_results, expected_regression_results)
def test_slice_with_masking(self, unmasked_column, slice_column):
"""
Test that masking a factor that uses slices as inputs does not mask the
slice data.
"""
sids = self.sids
asset_finder = self.asset_finder
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
# Create a filter that masks out all but a single asset.
unmasked_asset = asset_finder.retrieve_asset(sids[unmasked_column])
unmasked_asset_only = (AssetID().eq(unmasked_asset.sid))
# Asset used to create our slice. In the cases where this is different
# than `unmasked_asset`, our slice should still have non-missing data
# when used as an input to our custom factor. That is, it should not be
# masked out.
slice_asset = asset_finder.retrieve_asset(sids[slice_column])
returns = Returns(window_length=2, inputs=[self.col])
returns_slice = returns[slice_asset]
returns_results = self.run_pipeline(
Pipeline(columns={'returns': returns}),
start_date,
end_date,
)
returns_results = returns_results['returns'].unstack()
class UsesSlicedInput(CustomFactor):
window_length = 1
inputs = [returns, returns_slice]
def compute(self, today, assets, out, returns, returns_slice):
# Ensure that our mask correctly affects the `returns` input
# and does not affect the `returns_slice` input.
assert returns.shape == (1, 1)
assert returns_slice.shape == (1, 1)
assert returns[0, 0] == \
returns_results.loc[today, unmasked_asset]
assert returns_slice[0, 0] == \
returns_results.loc[today, slice_asset]
columns = {'masked': UsesSlicedInput(mask=unmasked_asset_only)}
# Assertions about the expected data are made in the `compute` function
# of our custom factor above.
self.run_pipeline(Pipeline(columns=columns), start_date, end_date)
def test_non_existent_asset(self):
"""
Test that indexing into a term with a non-existent asset raises the
proper exception.
"""
my_asset = Asset(0, exchange="TEST")
returns = Returns(window_length=2, inputs=[self.col])
returns_slice = returns[my_asset]
class UsesSlicedInput(CustomFactor):
window_length = 1
inputs = [returns_slice]
def compute(self, today, assets, out, returns_slice):
pass
with self.assertRaises(NonExistentAssetInTimeFrame):
self.run_pipeline(
Pipeline(columns={'uses_sliced_input': UsesSlicedInput()}),
self.pipeline_start_date,
self.pipeline_end_date,
)
def test_factor_regression_method_two_factors(self, regression_length):
"""
Tests for `Factor.linear_regression` when passed another 2D factor
instead of a Slice.
"""
assets = self.assets
dates = self.dates
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
start_date_index = self.start_date_index
end_date_index = self.end_date_index
num_days = self.num_days
run_pipeline = self.run_pipeline
# The order of these is meant to align with the output of `linregress`.
outputs = ['beta', 'alpha', 'r_value', 'p_value', 'stderr']
# Ensure that the `linear_regression` method cannot be called with two
# 2D factors which have different masks.
returns_masked_1 = Returns(
window_length=5, inputs=[self.col], mask=AssetID().eq(1),
)
returns_masked_2 = Returns(
window_length=5, inputs=[self.col], mask=AssetID().eq(2),
)
with self.assertRaises(IncompatibleTerms):
returns_masked_1.linear_regression(
target=returns_masked_2, regression_length=regression_length,
)
returns_5 = Returns(window_length=5, inputs=[self.col])
returns_10 = Returns(window_length=10, inputs=[self.col])
regression_factor = returns_5.linear_regression(
target=returns_10, regression_length=regression_length,
)
columns = {
output: getattr(regression_factor, output)
for output in outputs
}
pipeline = Pipeline(columns=columns)
results = run_pipeline(pipeline, start_date, end_date)
output_results = {}
expected_output_results = {}
for output in outputs:
output_results[output] = results[output].unstack()
expected_output_results[output] = full_like(
output_results[output], nan,
)
# Run a separate pipeline that calculates returns starting
# (regression_length - 1) days prior to our start date. This is because
# we need (regression_length - 1) extra days of returns to compute our
# expected regressions.
columns = {'returns_5': returns_5, 'returns_10': returns_10}
results = run_pipeline(
Pipeline(columns=columns),
dates[start_date_index - (regression_length - 1)],
dates[end_date_index],
)
returns_5_results = results['returns_5'].unstack()
returns_10_results = results['returns_10'].unstack()
# On each day, for each asset, calculate the expected regression
# results of Y ~ X where Y is the asset's rolling 5 day returns and X
# is the asset's rolling 10 day returns. Each regression is calculated
# over `regression_length` days of data.
for day in range(num_days):
todays_returns_5 = returns_5_results.iloc[
day:day + regression_length
]
todays_returns_10 = returns_10_results.iloc[
day:day + regression_length
]
for asset, asset_returns_5 in todays_returns_5.iteritems():
asset_column = int(asset) - 1
asset_returns_10 = todays_returns_10[asset]
expected_regression_results = linregress(
y=asset_returns_5, x=asset_returns_10,
)
for i, output in enumerate(outputs):
expected_output_results[output][day, asset_column] = \
expected_regression_results[i]
for output in outputs:
output_result = output_results[output]
expected_output_result = DataFrame(
expected_output_results[output],
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(output_result, expected_output_result)
def test_factor_correlation_methods_two_factors(self, correlation_length):
"""
Tests for `Factor.pearsonr` and `Factor.spearmanr` when passed another
2D factor instead of a Slice.
"""
assets = self.assets
dates = self.dates
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
start_date_index = self.start_date_index
end_date_index = self.end_date_index
num_days = self.num_days
run_pipeline = self.run_pipeline
# Ensure that the correlation methods cannot be called with two 2D
# factors which have different masks.
returns_masked_1 = Returns(
window_length=5, inputs=[self.col], mask=AssetID().eq(1),
)
returns_masked_2 = Returns(
window_length=5, inputs=[self.col], mask=AssetID().eq(2),
)
with self.assertRaises(IncompatibleTerms):
returns_masked_1.pearsonr(
target=returns_masked_2, correlation_length=correlation_length,
)
with self.assertRaises(IncompatibleTerms):
returns_masked_1.spearmanr(
target=returns_masked_2, correlation_length=correlation_length,
)
returns_5 = Returns(window_length=5, inputs=[self.col])
returns_10 = Returns(window_length=10, inputs=[self.col])
pearson_factor = returns_5.pearsonr(
target=returns_10, correlation_length=correlation_length,
)
spearman_factor = returns_5.spearmanr(
target=returns_10, correlation_length=correlation_length,
)
columns = {
'pearson_factor': pearson_factor,
'spearman_factor': spearman_factor,
}
pipeline = Pipeline(columns=columns)
results = run_pipeline(pipeline, start_date, end_date)
pearson_results = results['pearson_factor'].unstack()
spearman_results = results['spearman_factor'].unstack()
# Run a separate pipeline that calculates returns starting
# (correlation_length - 1) days prior to our start date. This is
# because we need (correlation_length - 1) extra days of returns to
# compute our expected correlations.
columns = {'returns_5': returns_5, 'returns_10': returns_10}
results = run_pipeline(
Pipeline(columns=columns),
dates[start_date_index - (correlation_length - 1)],
dates[end_date_index],
)
returns_5_results = results['returns_5'].unstack()
returns_10_results = results['returns_10'].unstack()
# On each day, calculate the expected correlation coefficients
# between each asset's 5 and 10 day rolling returns. Each correlation
# is calculated over `correlation_length` days.
expected_pearson_results = full_like(pearson_results, nan)
expected_spearman_results = full_like(spearman_results, nan)
for day in range(num_days):
todays_returns_5 = returns_5_results.iloc[
day:day + correlation_length
]
todays_returns_10 = returns_10_results.iloc[
day:day + correlation_length
]
for asset, asset_returns_5 in todays_returns_5.iteritems():
asset_column = int(asset) - 1
asset_returns_10 = todays_returns_10[asset]
expected_pearson_results[day, asset_column] = pearsonr(
asset_returns_5, asset_returns_10,
)[0]
expected_spearman_results[day, asset_column] = spearmanr(
asset_returns_5, asset_returns_10,
)[0]
expected_pearson_results = DataFrame(
data=expected_pearson_results,
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(pearson_results, expected_pearson_results)
expected_spearman_results = DataFrame(
data=expected_spearman_results,
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(spearman_results, expected_spearman_results)
def test_regression_of_returns_factor(self,
returns_length,
regression_length):
"""
Tests for the built-in factor `RollingLinearRegressionOfReturns`.
"""
assets = self.assets
my_asset = self.my_asset
my_asset_column = self.my_asset_column
dates = self.dates
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
start_date_index = self.start_date_index
end_date_index = self.end_date_index
num_days = self.num_days
run_pipeline = self.run_pipeline
# The order of these is meant to align with the output of `linregress`.
outputs = ['beta', 'alpha', 'r_value', 'p_value', 'stderr']
returns = Returns(window_length=returns_length)
masks = self.cascading_mask, self.alternating_mask, NotSpecified
expected_mask_results = (
self.expected_cascading_mask_result,
self.expected_alternating_mask_result,
self.expected_no_mask_result,
)
for mask, expected_mask in zip(masks, expected_mask_results):
regression_factor = RollingLinearRegressionOfReturns(
target=my_asset,
returns_length=returns_length,
regression_length=regression_length,
mask=mask,
)
columns = {
output: getattr(regression_factor, output)
for output in outputs
}
pipeline = Pipeline(columns=columns)
if mask is not NotSpecified:
pipeline.add(mask, 'mask')
results = run_pipeline(pipeline, start_date, end_date)
if mask is not NotSpecified:
mask_results = results['mask'].unstack()
check_arrays(mask_results.values, expected_mask)
output_results = {}
expected_output_results = {}
for output in outputs:
output_results[output] = results[output].unstack()
expected_output_results[output] = full_like(
output_results[output], nan,
)
# Run a separate pipeline that calculates returns starting
# (regression_length - 1) days prior to our start date. This is
# because we need (regression_length - 1) extra days of returns to
# compute our expected regressions.
results = run_pipeline(
Pipeline(columns={'returns': returns}),
dates[start_date_index - (regression_length - 1)],
dates[end_date_index],
)
returns_results = results['returns'].unstack()
# On each day, calculate the expected regression results for Y ~ X
# where Y is the asset we are interested in and X is each other
# asset. Each regression is calculated over `regression_length`
# days of data.
for day in range(num_days):
todays_returns = returns_results.iloc[
day:day + regression_length
]
my_asset_returns = todays_returns.iloc[:, my_asset_column]
for asset, other_asset_returns in todays_returns.iteritems():
asset_column = int(asset) - 1
expected_regression_results = linregress(
y=other_asset_returns, x=my_asset_returns,
)
for i, output in enumerate(outputs):
expected_output_results[output][day, asset_column] = \
expected_regression_results[i]
for output in outputs:
output_result = output_results[output]
expected_output_result = DataFrame(
where(expected_mask, expected_output_results[output], nan),
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(output_result, expected_output_result)
def test_correlation_factors(self, returns_length, correlation_length):
"""
Tests for the built-in factors `RollingPearsonOfReturns` and
`RollingSpearmanOfReturns`.
"""
assets = self.assets
my_asset = self.my_asset
my_asset_column = self.my_asset_column
dates = self.dates
start_date = self.pipeline_start_date
end_date = self.pipeline_end_date
start_date_index = self.start_date_index
end_date_index = self.end_date_index
num_days = self.num_days
run_pipeline = self.run_pipeline
returns = Returns(window_length=returns_length)
masks = (self.cascading_mask, self.alternating_mask, NotSpecified)
expected_mask_results = (
self.expected_cascading_mask_result,
self.expected_alternating_mask_result,
self.expected_no_mask_result,
)
for mask, expected_mask in zip(masks, expected_mask_results):
pearson_factor = RollingPearsonOfReturns(
target=my_asset,
returns_length=returns_length,
correlation_length=correlation_length,
mask=mask,
)
spearman_factor = RollingSpearmanOfReturns(
target=my_asset,
returns_length=returns_length,
correlation_length=correlation_length,
mask=mask,
)
columns = {
'pearson_factor': pearson_factor,
'spearman_factor': spearman_factor,
}
pipeline = Pipeline(columns=columns)
if mask is not NotSpecified:
pipeline.add(mask, 'mask')
results = run_pipeline(pipeline, start_date, end_date)
pearson_results = results['pearson_factor'].unstack()
spearman_results = results['spearman_factor'].unstack()
if mask is not NotSpecified:
mask_results = results['mask'].unstack()
check_arrays(mask_results.values, expected_mask)
# Run a separate pipeline that calculates returns starting
# (correlation_length - 1) days prior to our start date. This is
# because we need (correlation_length - 1) extra days of returns to
# compute our expected correlations.
results = run_pipeline(
Pipeline(columns={'returns': returns}),
dates[start_date_index - (correlation_length - 1)],
dates[end_date_index],
)
returns_results = results['returns'].unstack()
# On each day, calculate the expected correlation coefficients
# between the asset we are interested in and each other asset. Each
# correlation is calculated over `correlation_length` days.
expected_pearson_results = full_like(pearson_results, nan)
expected_spearman_results = full_like(spearman_results, nan)
for day in range(num_days):
todays_returns = returns_results.iloc[
day:day + correlation_length
]
my_asset_returns = todays_returns.iloc[:, my_asset_column]
for asset, other_asset_returns in todays_returns.iteritems():
asset_column = int(asset) - 1
expected_pearson_results[day, asset_column] = pearsonr(
my_asset_returns, other_asset_returns,
)[0]
expected_spearman_results[day, asset_column] = spearmanr(
my_asset_returns, other_asset_returns,
)[0]
expected_pearson_results = DataFrame(
data=where(expected_mask, expected_pearson_results, nan),
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(pearson_results, expected_pearson_results)
expected_spearman_results = DataFrame(
data=where(expected_mask, expected_spearman_results, nan),
index=dates[start_date_index:end_date_index + 1],
columns=assets,
)
assert_frame_equal(spearman_results, expected_spearman_results)
def test_daily_returns_is_special_case_of_returns(self):
self.check_equivalent_terms({
'daily': DailyReturns(),
'manual_daily': Returns(window_length=2),
})
def test_factor_regression_method(self, returns_length, regression_length):
"""
Ensure that `Factor.linear_regression` is consistent with the built-in
factor `RollingLinearRegressionOfReturns`.
"""
my_asset = self.asset_finder.retrieve_asset(self.sids[0])
returns = Returns(window_length=returns_length, inputs=[self.col])
returns_slice = returns[my_asset]
regression = returns.linear_regression(
target=returns_slice,
regression_length=regression_length,
)
expected_regression = RollingLinearRegressionOfReturns(
target=my_asset,
returns_length=returns_length,
regression_length=regression_length,
)
# These built-ins construct their own Returns factor to use as inputs,
# so the only way to set our own inputs is to do so after the fact.
# This should not be done in practice. It is necessary here because we
# want Returns to use our random data as an input, but by default it is
# using USEquityPricing.close.
expected_regression.inputs = [returns, returns_slice]
columns = {
'regression': regression,
'expected_regression': expected_regression,
}
results = self.run_pipeline(
Pipeline(columns=columns),
self.pipeline_start_date,
self.pipeline_end_date,
)
regression_results = results['regression'].unstack()
expected_regression_results = results['expected_regression'].unstack()
assert_frame_equal(regression_results, expected_regression_results)
# Make sure we cannot call the linear regression method on factors or
# slices of dtype `datetime64[ns]`.
class DateFactor(CustomFactor):
window_length = 1
inputs = []
dtype = datetime64ns_dtype
window_safe = True
def compute(self, today, assets, out):
pass
date_factor = DateFactor()
date_factor_slice = date_factor[my_asset]
with self.assertRaises(TypeError):
date_factor.linear_regression(
target=returns_slice,
regression_length=regression_length,
)
with self.assertRaises(TypeError):
returns.linear_regression(
target=date_factor_slice,
regression_length=regression_length,
)