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
Contributors
Preface
Index

Colors, gradients, patterns, and shadows


Choosing an effective color scheme for data visualization is no easy task. Colors aren't simply used to make a chart look nicer. Besides distinguishing and suggesting associations between sets of data, they may also communicate information through aspects such as hue, contrast, saturation, or lightness. They can even influence the mood of the viewer. The choice of colors is never neutral. It may attract or repel the viewer from relevant information.

Other aspects may be important, depending on your audience. You may want to use gradients, bevels, and shadows for purely aesthetic reasons, but if your audience requires maximum accessibility, you may also need to consider the use of color-blind-safe palettes or patterns.

Configuring colors

Chart.js supports standard HTML/CSS color names and codes (see Chapter 2, Technology Fundamentals), which are assigned to properties that control fonts, strokes (lines, and borders), and fills. You can select a color...