更新时间：2021-07-02 18:12:51
cover
Title Page
R Data Analysis Cookbook
Second Edition
Copyright
Credits
About the Author
About the Reviewers
www.PacktPub.com
Why subscribe?
Customer Feedback
Preface
What this book covers
What you need for this book
Who this book is for
Conventions
Reader feedback
Customer support
Downloading the example code
Downloading the color images of this book
Errata
Piracy
Questions
Acquire and Prepare the Ingredients - Your Data
Introduction
Working with data
Reading data from CSV files
Getting ready
How to do it...
How it works...
There's more...
Handling different column delimiters
Handling column headers/variable names
Handling missing values
Reading strings as characters and not as factors
Reading data directly from a website
Reading XML data
Extracting HTML table data from a web page
Extracting a single HTML table from a web page
Reading JSON data
Reading data from fixed-width formatted files
Files with headers
Excluding columns from data
Reading data from R files and R libraries
Saving all objects in a session
Saving objects selectively in a session
Attaching/detaching R data files to an environment
Listing all datasets in loaded packages
Removing cases with missing values
Eliminating cases with NA for selected variables
Finding cases that have no missing values
Converting specific values to NA
Excluding NA values from computations
Replacing missing values with the mean
Imputing random values sampled from non-missing values
Removing duplicate cases
Identifying duplicates without deleting them
Rescaling a variable to specified min-max range
Rescaling many variables at once
See also
Normalizing or standardizing data in a data frame
Standardizing several variables simultaneously
