R is an open source statistical language used in many fields – economics, mathematics, data science, digital humanities, computer science, and the natural sciences, among others – and there are many free resources online to help you learn the language.
Searching for R
If you need to search for information related to R, keep a few things in mind:
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Search the tags for R at StackOverflow in their discussion boards.
This book is a problem-solution primer for using R to set up your data, pose your problems and get answers using a wide array of statistical tests. The book walks you through R basics and how to use R to accomplish a wide variety statistical operations. You'll be able to navigate the R system, enter and import data, manipulate datasets, calculate summary statistics, create statistical plots and customize their appearance, perform hypothesis tests such as the t-tests and analyses of variance, and build regression models. Examples are built around actual datasets to simulate real-world solutions, and programming basics are explained to assist those who do not have a development background. No prior knowledge of R or of programming is assumed, though you should have some experience with statistics.
This new edition to the classic book by ggplot2 creator Hadley Wickham highlights compatibility with knitr and RStudio. ggplot2 is a data visualization package for R that helps users create data graphics, including those that are multi-layered, with ease. With ggplot2, it's easy to: produce handsome, publication-quality plots with automatic legends created from the plot specification superimpose multiple layers (points, lines, maps, tiles, box plots) from different data sources with automatically adjusted common scales add customizable smoothers that use powerful modeling capabilities of R, such as loess, linear models, generalized additive models, and robust regression save any ggplot2 plot (or part thereof) for later modification or reuse create custom themes that capture in-house or journal style requirements and that can easily be applied to multiple plots approach a graph from a visual perspective, thinking about how each component of the data is represented on the final plot This book will be useful to everyone who has struggled with displaying data in an informative and attractive way. Some basic knowledge of R is necessary (e.g., importing data into R). ggplot2 is a mini-language specifically tailored for producing graphics, and you'll learn everything you need in the book. After reading this book you'll be able to produce graphics customized precisely for your problems, and you'll find it easy to get graphics out of your head and on to the screen or page.
The Inter-university Consortium for Political and Social Research (ICPSR) is a membership-based, non-profit data archive located at the Institute for Social Research at the University of Michigan. It serves member colleges and universities in the United States and abroad by providing: Access to the world's largest archive of computerized social science data, Training facilities for the study of quantitative social analysis techniques, Resources for social scientists using advanced computer technologies. PSU users get access to ICPSR by creating an individual account using their PSU e-mail ID. This is what identifies them as a PSU affiliate. We do not have IP access. Go to: http://www.icpsr.umich.edu/icpsrweb/ICPSR/index.jsp - See login at top left. Note: occasionally you will need to login using a computer on campus to validate that you are still a PSU affiliate.
A comprehensive source for US nationwide public opinion data from academic, commercial and media survey organizations such as ABC News, CBS News, Fox News, The Gallup Organization, Los Angeles Times, National Opinion Research Center, NBC News, New York Times, Princeton Survey Research Associates, the Program on International Policy Attitudes at the University of Maryland, USA Today and The Washington Post. iPOLL is organized at the question-level, providing the tools to sift through 350,000 questions asked on national public opinion surveys since 1935. Penn State users may need to register using their PSU email to create a user account and password to download data. To create an account select the login tab. When you log in make sure you select Pennsylvania State University as your affiliation.