Sec.B-Ch.2-Subsec.9：Data Transformation and Variable Engineering in R

Data Reshaping in R, Adding Variables, Value Assignment and Modification, and Advanced Uses of the mutate() Function

During the process of data analysis, adding new variables and modifying existing variables are common and important tasks. The dplyr package in R provides powerful tools to simplify these operations. In this section, we will introduce in detail how to use the mutate() function in the dplyr package to add new variables, as well as how to modify existing variables in a dataset through value assignment.