Reshaping Data from Long Format to Wide Format without "timevar" Feature

Replacing NAs with the Latest Non-NA Value Using R's zoo Package

Merging Multiple Data Frames in R: A Comprehensive Guide

Reshaping Data from Long to Wide Format in R: A Comprehensive Guide

Reshaping Multiple Sets of Measurement Columns into Single Columns Using R and reshape2 Package

Creating a Group Index for Values Connected Directly and Indirectly Using R's igraph Library

Summing a Variable by Group in R: A Comprehensive Guide

Understanding Data Aggregation in R: A Comprehensive Guide