Calculating Averages of Column B for Each Subset of Column A Based on Specified Granularity

Subsetting Survey Design Objects Dynamically in R

Understanding Factor Levels in R: How to Eliminate Unused Levels with droplevels()

Subsetting Nominal Variables in R: A Comparative Analysis of Data.table, dplyr, and Base R

Filtering Rows with Measurements for More Than One Year in R Using Data.table and dplyr Libraries

Filtering Data Frames Based on Multiple Conditions in Another Data Frame Using SQL and Non-SQL Methods

Mastering Subsetting in R: Techniques and Error Prevention Strategies