Grouping Rows in R

Steven Sanderson needs a GROUP BY clause:

Combining rows with the same column values is a fundamental task in data analysis and manipulation, especially when handling large datasets. This guide is tailored for beginner R programmers looking to efficiently merge rows using Base R, the dplyr package, and the data.table package. By the end of this guide, you will be able to seamlessly aggregate data in R, enhancing your data analysis capabilities.

Click through for several code examples.