R Analysis

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This wiki is designed to help anyone perform statistical analyses on their data using R. It is divided into 3 broad sections: the first section outlines basics of how R deals with data using built in data sets, the second will help you to read in and organize your own data, and the third will help to summarize, run stats, and output graphs of your data.

Each section is organized into a series of questions. Start from the beginning if you are new to R, or click on a question to go to a detailed answer and/or examples.

To get started, download R for free from the R website

Alternatively, for a better organized scripting environment with syntax highlighting, download Rstudio

Part 1: R basics

Part 2: Organizing your data

This section describes how to load in data files into a data frame, add or drop columns, create a new data frame from a subset of the full data, and generally get your data into the form you need so you can then conduct your analyses.

prep stuff: data sets & making a new script

First download the following data sets, and unzip them to a local folder:

(you can also find these in the bar.laboratory@gmail.com dropbox account, in the "\stats meetings\data sets" folder - please make copies for yourself as these should remain in this folder as originals)

how to read your data into R

how to fill out and complete your main data frame

how to select a subset of your main data frame

reorganizing your data for export to Excel/SPSS

Part 3: Analyzing your data

This section outlines how to perform descriptive stats, inferential stats, and output graphs once your data frame is organized

Performing ANOVAs

Means tables and simple plots

Follow-up tests

Following up on significant main effect of a factor with more than 2 levels
Following up on significant interaction

Full graphs with error bars