Files
drift/training/walk_forward.py
T
Mark Aron Szulyovszky 1cd0119589 feat(DataLoader): caching MVP, added ability to use standard scaling for exogenous data, scaling is now also done before feature selection (#105)
* fix(FeatureExtractor): apply log to transform some series to normality

* feat(DataLoader): add ability of not returning returns when they're not needed (exogenous data), applied log to certain features

* feat(FeatureExtractors): added standard scaling for exogenous data

* feat(FeatureSelection): scale data with the passed in scaler before doing feature-selection

* fix(Config): sweep config

* feat(Models): output probability, store it

* feat(Core): added caching to select_features() and load_data()

* fix(Dependencies): added diskcache

* fix(Training): error when creating results DF

* feat(Models): added xgboost, fixed tests

* refactor(Cache): moved hashing to a separate function, created wrapper functions to separate business logic and caching

* fix(Tests): new syntax

* fix(Model): XGboost can't handle -1 class, so we'll use the deprecated label_encoder fornow

* fix(Model): XGBoost config

* feat(Cache): add run_clear_cache script

* fix(Pipeline) accidentally re-instatiating all_predictions for each asset
2022-01-04 11:44:35 +01:00

83 lines
3.0 KiB
Python

import pandas as pd
from models.base import Model
import numpy as np
from utils.helpers import get_first_valid_return_index
from tqdm import tqdm
from sklearn.base import clone
def walk_forward_train_test(
model_name: str,
model: Model,
X: pd.DataFrame,
y: pd.Series,
target_returns: pd.Series,
expanding_window: bool,
window_size: int,
retrain_every: int,
scaler,
) -> tuple[pd.Series, pd.Series, pd.DataFrame]:
assert len(X) == len(y)
predictions = pd.Series(index=y.index).rename(model_name)
probabilities = pd.DataFrame(index=y.index)
models = pd.Series(index=y.index).rename(model_name)
first_nonzero_return = max(get_first_valid_return_index(target_returns), get_first_valid_return_index(X.iloc[:,0]))
train_from = first_nonzero_return + window_size + 1
train_till = len(y)
iterations_before_retrain = 0
if model.only_column is not None:
X = X[[column for column in X.columns if model.only_column in column]]
is_scaling_on = scaler is not None and model.data_scaling == 'scaled'
if is_scaling_on:
scaler = clone(scaler)
for index in tqdm(range(train_from, train_till)):
if iterations_before_retrain <= 0 or pd.isna(models[index-1]):
if expanding_window:
train_window_start = first_nonzero_return
else:
train_window_start = index - window_size - 1
train_window_end = index - 1
if is_scaling_on:
# We need to fit on the expanding window data slice
# This is our only way to avoid lookahead bias
X_expanding_window = X[first_nonzero_return:train_window_end]
scaler.fit(X_expanding_window.values)
X_slice = X[train_window_start:train_window_end]
y_slice = y[train_window_start:train_window_end]
if is_scaling_on:
X_slice = scaler.transform(X_slice.values)
else:
X_slice = X_slice.to_numpy()
current_model = model.clone()
current_model.fit(X_slice, y_slice.to_numpy())
iterations_before_retrain = retrain_every
else:
current_model = models[index-1]
models[index] = current_model
next_timestep = X.iloc[index].to_numpy().reshape(1, -1)
if is_scaling_on:
next_timestep = scaler.transform(next_timestep)
prediction, probs = current_model.predict(next_timestep)
predictions[index] = prediction
if len(probabilities.columns) != len(probs):
probabilities = probabilities.reindex(columns = ["prob_" + str(num) for num in range(0, len(probs.T))])
probabilities.iloc[index] = probs
iterations_before_retrain -= 1
return models, predictions, probabilities