Book Image

Learn Chart.js

By : Helder da Rocha
Book Image

Learn Chart.js

By: Helder da Rocha

Overview of this book

Chart.js is a free, open-source data visualization library, maintained by an active community of developers in GitHub, where it rates as the second most popular data visualization library. If you want to quickly create responsive Web-based data visualizations for the Web, Chart.js is a great choice. This book guides the reader through dozens of practical examples, complete with code you can run and modify as you wish. It is a practical hands-on introduction to Chart.js. If you have basic knowledge of HTML, CSS and JavaScript you can learn to create beautiful interactive Web Canvas-based visualizations for your data using Chart.js. This book will help you set up Chart.js in a Web page and show how to create each one of the eight Chart.js chart types. You will also learn how to configure most properties that override Chart’s default styles and behaviors. Practical applications of Chart.js are exemplified using real data files obtained from public data portals. You will learn how to load, parse, filter and select the data you wish to display from those files. You will also learn how to create visualizations that reveal patterns in the data. This book is based on Chart.js version 2.7.3 and ES2015 JavaScript. By the end of the book, you will be able to create beautiful, efficient and interactive data visualizations for the Web using Chart.js.
Table of Contents (14 chapters)
Title Page
Copyright and Credits
About Packt

Radial scales

Two Chart.js chart types use radial scales: radar and polarArea. Radial charts that have a single scale are configured with the properties listed here. Some properties are similar to the properties used in Cartesian scales, but they have fewer configuration options:






Configure point labels



Configure chart ticks



Configures radial grid lines



Configure concentric grid lines

Configuration objects for radial scales

These properties are used directly inside the options.scale object. For example:

options: {
     scale: {
         ticks: {…},
         angleLines: {…},
         gridLines: {…},
         pointLabels: {…}

Configuring point labels

Point labels are the labels that are displayed around the radial chart, at each angle line. Tick labels are placed inside the chart over the first angle line and have a backdrop. Point labels are configured with the scale.pointLabels property, which is an object...