Files
drift/utils/walk_forward.py
T
Mark Aron Szulyovszky 1eaba0c221 fix(Evaluate): ignore empty data at evaluation time, add backtesting metrics (sharpe, etc), fixed crash when predicting 0.0 (#23)
* fix(Evaluate): ignore empty data at evaluation time, so we don't inflate the model's performance

* refactor(Pipeline): pass in data_loader arguments to the pipeline

* feat(Evaluation): added sharpe, sortino, etc

* fix: Took out the method to fill NaN numbers with 0s. This way in evaluation we can ignore NaN values.

* fix: Fix of the fix added fillna back. Either we root out NaN lines in the very beginning or we stick with the method you created.

Co-authored-by: Daniel Szemerey <szemy2@gmail.com>
2021-12-15 21:11:12 +01:00

49 lines
1.7 KiB
Python

import pandas as pd
from sklearn.base import clone
from utils.typing import SKLearnModel
import numpy as np
def walk_forward_train_test(
model_name: str,
model: SKLearnModel,
X: pd.DataFrame,
y: pd.Series,
window_size: int,
retrain_every: int
) -> tuple[pd.Series, pd.Series]:
predictions = pd.Series(index=y.index).rename(model_name)
models = pd.Series(index=y.index).rename(model_name)
train_from = window_size
train_till = y.index[-1]
iterations_since_retrain = 0
for i in range(train_from, train_till):
iterations_since_retrain += 1
window_start = i - window_size
window_end = i
X_slice = X[window_start:window_end]
y_slice = y[window_start:window_end]
if iterations_since_retrain >= retrain_every or pd.isna(models[i-1]):
current_model = clone(model)
current_model.fit(X_slice.to_numpy(), y_slice.to_numpy())
iterations_since_retrain = 0
else:
current_model = models[i-1]
models[window_end] = current_model
next_timestep = X.iloc[window_end+1].to_numpy().reshape(1, -1)
prediction = current_model.predict(next_timestep).item()
if prediction == 0.:
# TODO: we shouldn't feed in zeros to the model, and skip training / predicting when everything is 0
# print("Warning: model predicted 0., overriding it with 0.0001")
prediction = 0.0001
predictions[window_end+1] = prediction
return models, predictions