Book Image

Modern Time Series Forecasting with Python

By : Manu Joseph
5 (1)
Book Image

Modern Time Series Forecasting with Python

5 (1)
By: Manu Joseph

Overview of this book

We live in a serendipitous era where the explosion in the quantum of data collected and a renewed interest in data-driven techniques such as machine learning (ML), has changed the landscape of analytics, and with it, time series forecasting. This book, filled with industry-tested tips and tricks, takes you beyond commonly used classical statistical methods such as ARIMA and introduces to you the latest techniques from the world of ML. This is a comprehensive guide to analyzing, visualizing, and creating state-of-the-art forecasting systems, complete with common topics such as ML and deep learning (DL) as well as rarely touched-upon topics such as global forecasting models, cross-validation strategies, and forecast metrics. You’ll begin by exploring the basics of data handling, data visualization, and classical statistical methods before moving on to ML and DL models for time series forecasting. This book takes you on a hands-on journey in which you’ll develop state-of-the-art ML (linear regression to gradient-boosted trees) and DL (feed-forward neural networks, LSTMs, and transformers) models on a real-world dataset along with exploring practical topics such as interpretability. By the end of this book, you’ll be able to build world-class time series forecasting systems and tackle problems in the real world.
Table of Contents (26 chapters)
1
Part 1 – Getting Familiar with Time Series
6
Part 2 – Machine Learning for Time Series
13
Part 3 – Deep Learning for Time Series
20
Part 4 – Mechanics of Forecasting

Detecting and correcting for trends

In Chapter 5, Time Series Forecasting as Regression, we talked about forecasting being a difficult problem because it is intrinsically an extrapolation problem. Trends are one of the major contributors to forecasting being an extrapolation problem. If we have a time series that is trending upward, any model that attempts to forecast it needs to extrapolate beyond the range of values it has seen during training. ARIMA handles this using autoregression, whereas exponential smoothing handles it by modeling the trend explicitly. But standard regression may not be naturally suited to extrapolation. However, with suitable features, such as lags, it can start to do that. But if we can confidently estimate and extract a trend in the time series, we can simplify the problem we have to apply regression to by detrending the time series.

But before we move ahead, it is worth learning about two major types of trends.

Deterministic and stochastic trends

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