feat(FeatureExtraction): added fractionally differentiated returns to remove lagged returns (#95)

* feat(FeatureExtraction): added fractionally differentiated returns to remove lagged returns

* fix(Sweep): config

* fix(Sweep): name

* fix(Sweep): grid

* feat(Config): separated sliding_window_size_level1 & sliding_window_size_level2

* feat(Dependencies): added ray, now using it to parallel process feature extraction

* fix(Dependencies): added pip explicitly

* fix(Dependencies): removed ray from root

* fix(Models): average model was probably not taking the right timestamp to average

* feat(Config): separated expanding_window_level1 & expanding_window_level2

* fix(Config): set n_features_to_select to the optimal 30
This commit is contained in:
Mark Aron Szulyovszky
2021-12-28 22:50:09 +01:00
committed by GitHub
parent cc70d3f907
commit f762ceed2a
13 changed files with 626 additions and 417 deletions
+13 -7
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@@ -7,10 +7,13 @@ from models.model_map import model_names_classification, model_names_regression
def get_default_level_1_config() -> tuple[dict, dict, dict]:
training_config = dict(
dimensionality_reduction = False,
dimensionality_reduction = True,
feature_selection = True,
expanding_window = False,
sliding_window_size = 380,
n_features_to_select = 30,
expanding_window_level1 = False,
expanding_window_level2 = False,
sliding_window_size_level1 = 380,
sliding_window_size_level2 = 1,
retrain_every = 20,
scaler = 'minmax', # 'normalize' 'minmax' 'standardize' 'none'
include_original_data_in_ensemble = False,
@@ -46,8 +49,11 @@ def get_default_level_2_config() -> tuple[dict, dict, dict]:
training_config = dict(
dimensionality_reduction = True,
feature_selection = True,
expanding_window = True,
sliding_window_size = 380,
n_features_to_select = 30,
expanding_window_level1 = True,
expanding_window_level2 = False,
sliding_window_size_level1 = 380,
sliding_window_size_level2 = 1,
retrain_every = 20,
scaler = 'minmax', # 'normalize' 'minmax' 'standardize' 'none'
include_original_data_in_ensemble = False,
@@ -59,8 +65,8 @@ def get_default_level_2_config() -> tuple[dict, dict, dict]:
load_other_assets= True,
log_returns= True,
forecasting_horizon = 1,
own_features = ['level_2', 'date_days', 'lags_up_to_5'],
other_features = ['level_2', 'lags_up_to_5'],
own_features = ['level_2', 'date_days', 'fracdiff'],
other_features = ['level_2', 'fracdiff'],
index_column= 'int',
method= 'classification',
no_of_classes= 'three-balanced'
+4
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@@ -21,4 +21,8 @@ dependencies:
- wandb
- python-dotenv
- tscv
- pip
- pip:
- fracdiff
- ray
prefix: /usr/local/anaconda3/envs/quant
+537 -140
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File diff suppressed because one or more lines are too long
@@ -1,6 +1,7 @@
from feature_extractors.feature_extractors import feature_lag, feature_mom, feature_ROC, feature_RSI, feature_STOD, feature_STOK, feature_vol, feature_day_of_month, feature_day_of_week, feature_month, feature_debug_future_lookahead
from utils.typing import FeatureExtractorConfig
from utils.helpers import flatten
from feature_extractors.fractional_differentiation import feature_fractional_differentiation
__presets = dict(
debug_future_lookahead = [('debug_future', feature_debug_future_lookahead, [1])],
@@ -22,6 +23,7 @@ __presets = dict(
rsi = [('rsi', feature_ROC, [10, 30, 100])],
stod = [('stod', feature_STOD, [10, 30, 200])],
stok = [('stok', feature_STOK, [10, 30, 200])],
fracdiff = [('fracdiff', feature_fractional_differentiation, [10, 30])],
)
presets = __presets | dict(
@@ -0,0 +1,10 @@
from fracdiff.sklearn import FracdiffStat
import pandas as pd
import numpy as np
def feature_fractional_differentiation(df: pd.DataFrame, period: int, is_log_return: bool) -> pd.Series:
feature_selector = FracdiffStat(window = period)
input_series = df["close"].to_numpy().reshape(-1, 1)
feature_selector.fit(input_series)
result = feature_selector.transform(input_series)
return pd.Series(np.log(result.squeeze()), index = df.index)
-240
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@@ -1,240 +0,0 @@
"""
Fractional differentiation is a technique to make a time series stationary but also
retain as much memory as possible. This is done by differencing by a positive real
number. Fractionally differenced series can be used as a feature in machine learning
process.
"""
import numpy as np
import pandas as pd
class FractionalDifferentiation:
"""
FractionalDifferentiation class encapsulates the functions that can
be used to compute fractionally differentiated series.
"""
@staticmethod
def get_weights(diff_amt, size):
"""
Advances in Financial Machine Learning, Chapter 5, section 5.4.2, page 79.
The helper function generates weights that are used to compute fractionally
differentiated series. It computes the weights that get used in the computation
of fractionally differentiated series. This generates a non-terminating series
that approaches zero asymptotically. The side effect of this function is that
it leads to negative drift "caused by an expanding window's added weights"
(see page 83 AFML)
When diff_amt is real (non-integer) positive number then it preserves memory.
The book does not discuss what should be expected if d is a negative real
number. Conceptually (from set theory) negative d leads to set of negative
number of elements. And that translates into a set whose elements can be
selected more than once or as many times as one chooses (multisets with
unbounded multiplicity) - see http://faculty.uml.edu/jpropp/msri-up12.pdf.
:param diff_amt: (float) Differencing amount
:param size: (int) Length of the series
:return: (np.ndarray) Weight vector
"""
# The algorithm below executes the iterative estimation (section 5.4.2, page 78)
weights = [1.] # create an empty list and initialize the first element with 1.
for k in range(1, size):
weights_ = -weights[-1] * (diff_amt - k + 1) / k # compute the next weight
weights.append(weights_)
# Now, reverse the list, convert into a numpy column vector
weights = np.array(weights[::-1]).reshape(-1, 1)
return weights
@staticmethod
def frac_diff(series, diff_amt, thresh=0.01):
"""
Advances in Financial Machine Learning, Chapter 5, section 5.5, page 82.
References:
https://www.wiley.com/en-us/Advances+in+Financial+Machine+Learning-p-9781119482086
https://wwwf.imperial.ac.uk/~ejm/M3S8/Problems/hosking81.pdf
https://en.wikipedia.org/wiki/Fractional_calculus
The steps are as follows:
- Compute weights (this is a one-time exercise)
- Iteratively apply the weights to the price series and generate output points
This is the expanding window variant of the fracDiff algorithm
Note 1: For thresh-1, nothing is skipped
Note 2: diff_amt can be any positive fractional, not necessarility bounded [0, 1]
:param series: (pd.Series) A time series that needs to be differenced
:param diff_amt: (float) Differencing amount
:param thresh: (float) Threshold or epsilon
:return: (pd.DataFrame) Differenced series
"""
# 1. Compute weights for the longest series
weights = get_weights(diff_amt, series.shape[0])
# 2. Determine initial calculations to be skipped based on weight-loss threshold
weights_ = np.cumsum(abs(weights))
weights_ /= weights_[-1]
skip = weights_[weights_ > thresh].shape[0]
# 3. Apply weights to values
output_df = {}
for name in series.columns:
series_f = series[[name]].fillna(method='ffill').dropna()
output_df_ = pd.Series(index=series.index, dtype='float64')
for iloc in range(skip, series_f.shape[0]):
loc = series_f.index[iloc]
# At this point all entries are non-NAs so no need for the following check
# if np.isfinite(series.loc[loc, name]):
output_df_[loc] = np.dot(weights[-(iloc + 1):, :].T, series_f.loc[:loc])[0, 0]
output_df[name] = output_df_.copy(deep=True)
output_df = pd.concat(output_df, axis=1)
return output_df
@staticmethod
def get_weights_ffd(diff_amt, thresh, lim):
"""
Advances in Financial Machine Learning, Chapter 5, section 5.4.2, page 83.
The helper function generates weights that are used to compute fractionally
differentiate dseries. It computes the weights that get used in the computation
of fractionally differentiated series. The series is of fixed width and same
weights (generated by this function) can be used when creating fractional
differentiated series.
This makes the process more efficient. But the side-effect is that the
fractionally differentiated series is skewed and has excess kurtosis. In
other words, it is not Gaussian any more.
The discussion of positive and negative d is similar to that in get_weights
(see the function get_weights)
:param diff_amt: (float) Differencing amount
:param thresh: (float) Threshold for minimum weight
:param lim: (int) Maximum length of the weight vector
:return: (np.ndarray) Weight vector
"""
weights = [1.]
k = 1
# The algorithm below executes the iterativetive estimation (section 5.4.2, page 78)
# The output weights array is of the indicated length (specified by lim)
ctr = 0
while True:
# compute the next weight
weights_ = -weights[-1] * (diff_amt - k + 1) / k
if abs(weights_) < thresh:
break
weights.append(weights_)
k += 1
ctr += 1
if ctr == lim - 1: # if we have reached the size limit, exit the loop
break
# Now, reverse the list, convert into a numpy column vector
weights = np.array(weights[::-1]).reshape(-1, 1)
return weights
@staticmethod
def frac_diff_ffd(series, diff_amt, thresh=1e-5):
"""
Advances in Financial Machine Learning, Chapter 5, section 5.5, page 83.
References:
* https://www.wiley.com/en-us/Advances+in+Financial+Machine+Learning-p-9781119482086
* https://wwwf.imperial.ac.uk/~ejm/M3S8/Problems/hosking81.pdf
* https://en.wikipedia.org/wiki/Fractional_calculus
The steps are as follows:
- Compute weights (this is a one-time exercise)
- Iteratively apply the weights to the price series and generate output points
Constant width window (new solution)
Note 1: thresh determines the cut-off weight for the window
Note 2: diff_amt can be any positive fractional, not necessarity bounded [0, 1].
:param series: (pd.Series) A time series that needs to be differenced
:param diff_amt: (float) Differencing amount
:param thresh: (float) Threshold for minimum weight
:return: (pd.DataFrame) A data frame of differenced series
"""
# 1) Compute weights for the longest series
weights = get_weights_ffd(diff_amt, thresh, series.shape[0])
width = len(weights) - 1
# 2) Apply weights to values
# 2.1) Start by creating a dictionary to hold all the fractionally differenced series
output_df = {}
# 2.2) compute fractionally differenced series for each stock
for name in series.columns:
series_f = series[[name]].fillna(method='ffill').dropna()
temp_df_ = pd.Series(index=series.index, dtype='float64')
for iloc1 in range(width, series_f.shape[0]):
loc0 = series_f.index[iloc1 - width]
loc1 = series.index[iloc1]
# At this point all entries are non-NAs, hence no need for the following check
# if np.isfinite(series.loc[loc1, name]):
temp_df_[loc1] = np.dot(weights.T, series_f.loc[loc0:loc1])[0, 0]
output_df[name] = temp_df_.copy(deep=True)
# transform the dictionary into a data frame
output_df = pd.concat(output_df, axis=1)
return output_df
def get_weights(diff_amt, size):
""" This is a pass-through function """
return FractionalDifferentiation.get_weights(diff_amt, size)
def frac_diff(series, diff_amt, thresh=0.01):
""" This is a pass-through function """
return FractionalDifferentiation.frac_diff(series, diff_amt, thresh)
def get_weights_ffd(diff_amt, thresh, lim):
""" This is a pass-through function """
return FractionalDifferentiation.get_weights_ffd(diff_amt, thresh, lim)
def frac_diff_ffd(series, diff_amt, thresh=1e-5):
"""
Advances in Financial Machine Learning, Chapter 5, section 5.5, page 83.
References:
* https://www.wiley.com/en-us/Advances+in+Financial+Machine+Learning-p-9781119482086
* https://wwwf.imperial.ac.uk/~ejm/M3S8/Problems/hosking81.pdf
* https://en.wikipedia.org/wiki/Fractional_calculus
The steps are as follows:
- Compute weights (this is a one-time exercise)
- Iteratively apply the weights to the price series and generate output points
Constant width window (new solution)
Note 1: thresh determines the cut-off weight for the window
Note 2: diff_amt can be any positive fractional, not necessarity bounded [0, 1].
:param series: (pd.Series) A time series that needs to be differenced
:param diff_amt: (float) Differencing amount
:param thresh: (float) Threshold for minimum weight
:return: (pd.DataFrame) A data frame of differenced series
"""
return FractionalDifferentiation.frac_diff_ffd(series, diff_amt, thresh)
+2 -2
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@@ -4,7 +4,7 @@ import pandas as pd
from models.base import Model, SKLearnModel
from sklearn.decomposition import PCA
def select_features(X: pd.DataFrame, y: pd.Series, model: Model, min_features_to_select: int, backup_model: SKLearnModel) -> pd.DataFrame:
def select_features(X: pd.DataFrame, y: pd.Series, model: Model, n_features_to_select: int, backup_model: SKLearnModel) -> pd.DataFrame:
''' Select features using RFECV, returns a pd.DataFrame (X) with only the selected features.'''
if model.model_type != 'ml': return X
@@ -16,7 +16,7 @@ def select_features(X: pd.DataFrame, y: pd.Series, model: Model, min_features_to
feat_selector_model = backup_model.model
# selector = RFECV(feat_selector_model, cv = cv, step=5, min_features_to_select=min_features_to_select)
selector = RFE(feat_selector_model, n_features_to_select=10)
selector = RFE(feat_selector_model, n_features_to_select= n_features_to_select)
selector = selector.fit(X, y)
print("Kept %d features out of %d" % (selector.n_features_, X.shape[1]))
+1 -1
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@@ -18,7 +18,7 @@ class StaticAverageModel(Model):
def predict(self, X):
# Make sure there's data to average
assert X.shape[1] > 0
prediction = np.average(X[0])
prediction = np.average(X[-1])
return np.array([prediction])
def clone(self):
+8 -7
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@@ -8,6 +8,8 @@ from utils.helpers import get_first_valid_return_index, weighted_average
from config import get_default_level_1_config, get_default_level_2_config, validate_config, get_model_name
from feature_selection.feature_selection import select_features
from feature_selection.dim_reduction import reduce_dimensionality
import ray
ray.init()
def setup_pipeline(project_name:str, with_wandb: bool, sweep: bool):
model_config, training_config, data_config = get_default_level_2_config()
@@ -39,7 +41,7 @@ def pipeline(project_name:str, wandb, sweep:bool, model_config:dict, training_co
original_X = X.copy()
first_valid_index = get_first_valid_return_index(X.iloc[:,0])
samples_to_train = len(y) - first_valid_index
if samples_to_train < training_config['sliding_window_size'] * 3:
if samples_to_train < training_config['sliding_window_size_level1'] * 3:
print("Not enough samples to train")
continue
@@ -52,10 +54,9 @@ def pipeline(project_name:str, wandb, sweep:bool, model_config:dict, training_co
print("Feature Selection started")
# TODO: this needs to be done per model!
backup_model = default_feature_selector_regression if data_config['method'] == 'regression' else default_feature_selector_classification
X = select_features(X, y, model_config['level_1_models'][0][1], min_features_to_select = 10, backup_model = backup_model)
X = select_features(X, y, model_config['level_1_models'][0][1], n_features_to_select = training_config['n_features_to_select'], backup_model = backup_model)
print("Feature Selection ended")
# 3. Train Level-1 models
current_result, current_predictions = run_single_asset_trainig(
ticker_to_predict = asset,
@@ -65,8 +66,8 @@ def pipeline(project_name:str, wandb, sweep:bool, model_config:dict, training_co
target_returns = target_returns,
models = model_config['level_1_models'],
method = data_config['method'],
expanding_window = training_config['expanding_window'],
sliding_window_size = training_config['sliding_window_size'],
expanding_window = training_config['expanding_window_level1'],
sliding_window_size = training_config['sliding_window_size_level1'],
retrain_every = training_config['retrain_every'],
scaler = training_config['scaler'],
no_of_classes = data_config['no_of_classes'],
@@ -90,8 +91,8 @@ def pipeline(project_name:str, wandb, sweep:bool, model_config:dict, training_co
target_returns = target_returns,
models = [model_config['level_2_model']],
method = data_config['method'],
expanding_window = training_config['expanding_window'],
sliding_window_size = training_config['sliding_window_size'],
expanding_window = training_config['expanding_window_level2'],
sliding_window_size = training_config['sliding_window_size_level2'],
retrain_every = training_config['retrain_every'],
scaler = training_config['scaler'],
no_of_classes = data_config['no_of_classes'],
+17 -11
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@@ -1,23 +1,28 @@
program: run_sweep.py
method: bayes
method: grid
project: price-forecasting
name: Feature selection
name: Fractional differentiation / number of features
metric:
goal: maximize
name: sharpe
parameters:
path :
value: 'data/'
expanding_window:
expanding_window_level1:
value: True
sliding_window_size:
expanding_window_level2:
value: False
sliding_window_size_level1:
value: 380
sliding_window_size_level2:
value: 1
feature_selection:
values: [True, False]
value: True
n_features_to_select:
values: [10, 20, 30]
distribution: categorical
dimensionality_reduction:
values: [True, False]
distribution: categorical
value: True
retrain_every:
value: 20
scaler:
@@ -27,8 +32,7 @@ parameters:
method:
value: 'classification'
no_of_classes:
values: ['two', 'three-balanced', 'three-imbalanced']
distribution: categorical
value: 'three-balanced'
forecasting_horizon:
value: 1
load_other_assets:
@@ -42,6 +46,8 @@ parameters:
level_2_model:
value: "Ensemble_Average"
own_features:
value: ['date_days', 'level_2', 'lags_up_to_5']
values: [['date_days', 'level_2', 'lags_up_to_5'], ['date_days', 'level_2', 'fracdiff']]
distribution: categorical
other_features:
value: ['level_2', 'lags_up_to_5']
values: [['level_2', 'lags_up_to_5'], ['level_2', 'fracdiff']]
distribution: categorical
+13 -2
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@@ -8,12 +8,23 @@ metric:
parameters:
path :
value: 'data/'
expanding_window:
expanding_window_level1:
values: [True, False]
distribution: categorical
sliding_window_size:
expanding_window_level2:
value: False
feature_selection:
value: True
n_features_to_select:
values: [10, 20, 30]
distribution: categorical
dimensionality_reduction:
value: True
sliding_window_size_level1:
values: [180, 280, 380, 480, 580]
distribution: categorical
sliding_window_size_level2:
value: 1
retrain_every:
values: [10, 20, 30]
distribution: categorical
+15 -2
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@@ -8,10 +8,23 @@ metric:
parameters:
path :
value: 'data/'
expanding_window:
expanding_window_level1:
values: [True, False]
distribution: categorical
sliding_window_size:
expanding_window_level2:
values: [True, False]
distribution: categorical
feature_selection:
value: True
n_features_to_select:
values: [10, 20, 30]
distribution: categorical
dimensionality_reduction:
value: True
sliding_window_size_level1:
values: [180, 280, 380]
distribution: categorical
sliding_window_size_level2:
values: [180, 280, 380]
distribution: categorical
retrain_every:
+4 -5
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@@ -1,11 +1,9 @@
#%%
import pandas as pd
import os
import numpy as np
from utils.typing import FeatureExtractor
from typing import Literal
#%%
import ray
def get_crypto_assets(path: str) -> list[str]:
return sorted([f.split('.')[0] for f in os.listdir(path) if os.path.isfile(os.path.join(path,f)) and 'USD' in f and not f.startswith('.')])
@@ -40,13 +38,14 @@ def load_data(path: str,
other_files = [f for f in files if load_other_assets == True and f.startswith(target_asset) == False]
files = target_file + other_files
def is_target_asset(target_asset: str, file: str): return file.split('.')[0].startswith(target_asset)
dfs = [__load_df(
futures = [__load_df.remote(
path=os.path.join(path,f),
prefix=f.split('.')[0],
returns='log_returns' if log_returns else 'returns',
feature_extractors=own_features if is_target_asset(target_asset, f) else other_features,
narrow_format=narrow_format,
) for f in files]
dfs = ray.get(futures)
if narrow_format:
dfs = pd.concat(dfs, axis=0).fillna(0.)
else:
@@ -78,6 +77,7 @@ def load_data(path: str,
return X, y, forward_returns
@ray.remote
def __load_df(path: str,
prefix: str,
returns: Literal['price', 'returns', 'log_returns'],
@@ -123,7 +123,6 @@ def __apply_feature_extractors(df: pd.DataFrame,
return df
# %%
def __create_target_cum_forward_returns(df: pd.DataFrame, source_column: str, period: int) -> pd.Series:
assert period > 0
return df[source_column].shift(-period)