Book Image

R for Data Science Cookbook (n)

By : Yu-Wei, Chiu (David Chiu)
Book Image

R for Data Science Cookbook (n)

By: Yu-Wei, Chiu (David Chiu)

Overview of this book

This cookbook offers a range of data analysis samples in simple and straightforward R code, providing step-by-step resources and time-saving methods to help you solve data problems efficiently. The first section deals with how to create R functions to avoid the unnecessary duplication of code. You will learn how to prepare, process, and perform sophisticated ETL for heterogeneous data sources with R packages. An example of data manipulation is provided, illustrating how to use the “dplyr” and “data.table” packages to efficiently process larger data structures. We also focus on “ggplot2” and show you how to create advanced figures for data exploration. In addition, you will learn how to build an interactive report using the “ggvis” package. Later chapters offer insight into time series analysis on financial data, while there is detailed information on the hot topic of machine learning, including data classification, regression, clustering, association rule mining, and dimension reduction. By the end of this book, you will understand how to resolve issues and will be able to comfortably offer solutions to problems encountered while performing data analysis.
Table of Contents (19 chapters)
R for Data Science Cookbook
About the Author
About the Reviewer

Visualizing multivariate data using a biplot

In order to find how data and variables are mapped in regard to the principal component, you can use biplot, which plots data and projections of original features on to the first two components. In this recipe, we will demonstrate how to use biplot to plot both variables and data on the same figure.

Getting ready

Ensure that you have completed the previous recipe by generating a principal component object and saving it in variable eco.pca.

How to do it…

Perform the following steps to create a biplot:

  1. Create a scatter plot using component 1 and component 2:

    > plot(eco.pca$x[,1], eco.pca$x[,2], xlim=c(-6,6), ylim = c(-4,3))
    > text(eco.pca$x[,1], eco.pca$x[,2], eco.freedom[,2], cex=0.7, pos=4, col="red")

    Figure 20: The scatterplot of the first two components from the PCA result

  2. In addition, if you would like to add features on the plot, you can create the biplot using a generated principal component object:

    > rownames(eco.pca$x) =  as.character...