Book Image

R Data Visualization Cookbook

By : Gohil
Book Image

R Data Visualization Cookbook

By: Gohil

Overview of this book

If you are a data journalist, academician, student or freelance designer who wants to learn about data visualization, this book is for you. Basic knowledge of R programming is expected.
Table of Contents (12 chapters)
11
Index

A guide to contour maps


Contour maps have also been referred to as isometric maps or isopleth maps. Contour maps are used to display data related to temperature or topographic information. Most of the time, contour maps are used to display maps related to geology or mountains. The contour lines represent which sections of the mountains are steeper based on how close the contour lines are drawn from each other.

How to do it…

We can generate a contour map in R using the contour() function and also add a color to the contour using the filled.contour() function:

contour(volcano,  main = "Topographic map of a Volcano",col = "blue")
filled.contour(volcano, color.palette = terrain.colors,main = "Topographic map of a Volcano")

How it works…

In order to plot a simple contour plot, we will use the contour() function available with the basic R plotting functionality. The first argument passed in the contour() function is the data. The volcano dataset consists of topographic information on Auckland's Mauga...