Creating a Dataset with Linear Model Information Using R's Dplyr Library.

Creating Wide-to-Long DataFrames in R Using Vectorized Operations

Fixing R's Null vs NA Conundrum: How to Use NULL Correctly in Your Code

Understanding the Behavior of ddply in R: A Guide to Avoiding Confusion and Achieving Consistency

Grouping Data by Multiple Factors with Different Group Sizes in R Using Dplyr