Book Image

R Data Visualization Recipes

By : Vitor Bianchi Lanzetta
Book Image

R Data Visualization Recipes

By: Vitor Bianchi Lanzetta

Overview of this book

R is an open source language for data analysis and graphics that allows users to load various packages for effective and better data interpretation. Its popularity has soared in recent years because of its powerful capabilities when it comes to turning different kinds of data into intuitive visualization solutions. This book is an update to our earlier R data visualization cookbook with 100 percent fresh content and covering all the cutting edge R data visualization tools. This book is packed with practical recipes, designed to provide you with all the guidance needed to get to grips with data visualization using R. It starts off with the basics of ggplot2, ggvis, and plotly visualization packages, along with an introduction to creating maps and customizing them, before progressively taking you through various ggplot2 extensions, such as ggforce, ggrepel, and gganimate. Using real-world datasets, you will analyze and visualize your data as histograms, bar graphs, and scatterplots, and customize your plots with various themes and coloring options. The book also covers advanced visualization aspects such as creating interactive dashboards using Shiny By the end of the book, you will be equipped with key techniques to create impressive data visualizations with professional efficiency and precision.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Picking a custom number of contour lines


The previous recipe taught you how to create simple yet intuitive contour plots. This one will show how the number of levels/contour lines can be manually picked. There are mainly two arguments to do so and this recipe is demonstrating how these two works. Taking off from the previous recipe framework, let's see how we can go for another amount of lines/polygons.

How to do it...

Let us start with picking a custom number of contour lines:

  1.   Directly call bins to set the number of levels that the plot will display:
> library(ggplot2)
> ggplot(data = cars, aes(x = speed, y = dist)) + 
    geom_density_2d(aes(colour = ..level..), bins = 15)

A great number of bins may be difficult to visualize as the following image (Figure 8.4) shows:

Figure 8.4 - Using bins to set the number of contours

  1. The binwidth argument is an alternative:
> ggplot(data = cars, aes(x = speed, y = dist)) + 
   geom_density_2d(aes(colour = ..level..), binwidth = .0005)

Too few contours...