Collapsing Multiple Columns Containing the Same Variable into One Column Using R: Matrix Multiplication and tidyr Package

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

Reshaping DataFrames with Rbind: A Deeper Look into Gathering and Separating Data

Understanding Data Transformation: Reshaping from Long to Wide Format with R

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

Reshaping Column Values to Column Names in R Using reshape2 and tidyr Packages

Converting Wide Dataframe to Long Format with Quadruple Nesting Using R's melt Function