Subset Matrix in R by Row Numbers from Another Matrix Using R's Matrix Manipulation Capabilities

Subsetting Rows for Selecting on More Than One Value Using Droplevels in R

Understanding the Issue with Subseting Data from an Excel Sheet in R

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

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