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Table Of Contents
Time Series with PyTorch
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CV is a good approach for dealing with the stochastic nature of models. Unlike the simple train-test split, k-fold CV iterates over a dataset
times, ensuring each sample has the opportunity to be in both the training and test sets. In each iteration, the data is divided into
parts: one for validation and the remaining
for training. You calculate error metrics (such as RMSE) on each validation fold separately, then typically compute their mean or median to get an overall performance estimate. This provides a more robust evaluative assessment of model performance than fixed-origin designs, by giving a distribution of predictive performance across all available data.
When it comes to time-series CV (rolling origin), we are not limited to just non-overlapping folds. Two key approaches are worth considering: expanding windows and rolling windows.
Expanding-window CV starts with an initial training period that grows over time. For each iteration...