Introduction to R Statistical Software

About the Webinar

During this webinar, Dr. Heather Merk, The Ohio State University, introduces R software for statistical analysis, including

• Downloading this free software
• How to perform basic commands
• Where to learn more

Dr. Merk also demonstrates how R has been used to analyze tomato phenotypic data collected for the Solanaceae Coordinated Agricultural Project (SolCAP).

This one hour webinar has been divided into seven videos, which are listed in order on this webpage. The eighth video is the full webinar. The powerpoint slides (in pdf format), sample data files, and sample script are provided at the bottom of the page.

Learning Objectives

At the end of this webinar you should be able to do the following using R:

• Install and run R
• Find R packages, install, and load them
• Read in data and visualize distribution
• Test if there are differences between varieties (ANOVA using linear regression)
• Distinguish varieties (Means and t-test)
• Estimate variance components
• Use loops to simplify analysis

Videos

Watch the videos here or on a YouTube playlist

• Part 1 – An introduction to R statistical software and rationale for using R
• Part 2 – Basic commands using R and an introduction to text editors
• Part 3 – Description of the sample data, commands to check data importation, and creating histograms
• Part 4 – Analysis of simple ANOVA models
• Part 5 – Combining data sets and export tables
• Part 6 – Loops and where to get help
• Part 7 – Resources for learning R and the question and answer segment of the live webinar
• Full Video

Part 1

An introduction to R statistical software and rationale for using R.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 2

Basic commands using R and an introduction to text editors.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 3

Description of the sample data, commands to check data importation, and creating histograms.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 4

Analysis of simple ANOVA models.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 5

Combining data sets and export tables.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 6

Loops and where to get help.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Part 7

Resources for learning R and the question and answer segment of the live webinar.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Full Video

Full 58 minute webinar recording.

If you experience problems viewing this video connect to our YouTube channel or see the YouTube troubleshooting guide.

Register for, or watch other plant breeding and genomics “How To” webinars

About the Presenter

Dr. Merk combines her background in plant breeding and genetics with her interest in science communication in her role of content coordinator for the plant breeding and genomics community of practice at eXtension.org. As content coordinator, Dr. Merk leads development, review, and publication of online outreach materials targeted to plant breeding professionals. Dr. Merk obtained her Honors Bachelor of Science from the University of Toronto and her Ph.D. from The Pennsylvania State University.

References Cited

• Adler, J. 2010. R in a nutshell: a desktop quick reference. O’Reilly, Sebastapol, CA.
• Crawley, M. 2007. The R book. Wiley, Hoboken, NJ.
• Dalgaard, P. 2008. Introductory statistics with R. Springer-Verlaugh, NY.
• Murrell, P. 2006. R graphics. Chapman & Hall/CRC, NY.
• Zuur, A. F., E. N. Leno, and E.H.W.G. Meesters. 2009. A beginner’s guide to R. Springer, NY.

External Links

• Bates, D., M. Maechler, and B. Bolker. 2011. Package ‘lme4’ [Online]. The R Project for Statistical Computing. Available at: http://cran.r-project.org/web/packages/lme4/lme4.pdf (verified 13 Sept 2011).
• Cock, P. Programming in R [Online]. Molecular Organization and Assembly in Cells, The University of Warwick. Available at: http://www2.warwick.ac.uk/fac/sci/moac/degrees/modules/ch923/r_introduct… (verified 14 Sept 2011).
• Kim, D.Y. R basics [Online]. Illinois State University. Available at: http://math.illinoisstate.edu/dhkim/rstuff/rtutor.html (verified 8 Sept 2011).
• Martinez, M. R for biologists [Online]. The R Project for Statistical Computing. Available at: http://cran.r-project.org/doc/contrib/Martinez-RforBiologistv1.1.pdf (verified 8 Sept 2011).
• R Development Core Team. R Data import/export [Online]. The Comprehensive R Archive Network. Available at: http://cran.r-project.org (verified 9 Sept 2011).
• Solanaceae Coordinated Agricultural Project (SolCAP) [Online]. Michigan State University. Available at: http://www.solcap.msu.edu/ (verified 26 Aug 2011).
• Summer Institute for Statistical Genetics (SISG) at the University of Washington – http://www.biostat.washington.edu/suminst/sisg/general
• The R Project for Statistical Computing [Online]. The R Foundation for Statistical Computing. Available at: www.r-project.org/index.html (verified 4 Oct 2011).
• useR! Conference – http://www.r-project.org/conferences.html
• Verzani, J. SimpleR – Using R for introductory statistics [Online]. The R Project for Statistical Computing. Available at: http://cran.r-project.org/doc/contrib/Verzani-SimpleR.pdf (verified 8 Sept 2011).
   

Funding Statement

Development of this page was supported in part by the National Institute of Food and Agriculture (NIFA) Solanaceae Coordinated Agricultural Project, agreement 2009-85606-05673, administered by Michigan State University. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the United States Department of Agriculture.

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