Book Image

Hands-On Time Series Analysis with R

By : Rami Krispin
Book Image

Hands-On Time Series Analysis with R

By: Rami Krispin

Overview of this book

Time-series analysis is the art of extracting meaningful insights from, and revealing patterns in, time-series data using statistical and data visualization approaches. These insights and patterns can then be utilized to explore past events and forecast future values in the series. This book explores the basics of time-series analysis with R and lays the foundation you need to build forecasting models. You will learn how to preprocess raw time-series data and clean and manipulate data with packages such as stats, lubridate, xts, and zoo. You will analyze data using both descriptive statistics and rich data visualization tools in R including the TSstudio, plotly, and ggplot2 packages. The book then delves into traditional forecasting models such as time-series linear regression, exponential smoothing (Holt, Holt-Winter, and more) and Auto-Regressive Integrated Moving Average (ARIMA) models with the stats and forecast packages. You'll also work on advanced time-series regression models with machine learning algorithms such as random forest and Gradient Boosting Machine using the h2o package. By the end of this book, you will have developed the skills necessary for exploring your data, identifying patterns, and building a forecasting model using various traditional and machine learning methods.
Table of Contents (14 chapters)

The auto.arima function

One of the main challenges of forecasting with the ARIMA family of models is the cumbersome tuning process of the models. As we saw in this chapter, this process includes many manual steps that are required for verifying the structure of the series (stationary or non-stationary), data transformations, descriptive analysis with the ACF and PACF plots to identify the type of process, and eventually tune the model parameters. While it might take a few minutes to train an ARIMA model for a single series, it may not scale up if you have dozens of series to forecast.

The auto.arima function from the forecast package provides a solution to this issue. This algorithm automates the tuning process of the ARIMA model with the use of statistical methods to identify both the structure of the series (stationary or not) and type (seasonal or not), and sets the model&apos...