The problem statement wasn't provided, but based on the given response, it seems that the task is to provide a detailed explanation of how to merge two or more dataframes using the `merge()` function from R.

Adapting the R Function etm_to_df for Multiple Groups and Producing Customizable Cumulative Incidence Plots

Formatting Entire Sheet with Specific Style using R and xlsx: A Step-by-Step Guide to Creating Well-Formatted Excel Files with Ease.

Based on the provided specification, I'll write a complete R function that transforms a tdm matrix into a new matrix with an additional column representing the class of each term.

Pairplot Correlation Values: A Deeper Dive into Seaborn's PairGrid Functionality

Partial Least Squares Classification in R: A Comprehensive Guide to Building Effective Models

Creating Dynamic Inputs for UDFs in R Shiny Apps: A Step-by-Step Guide

Adding y-axes to a truncated barplot using ggplot2: A Step-by-Step Guide

Using Stargazer to Output Several Variables in the Same Row with Customized Regression Tables in R

Visualizing Row Means and Standard Deviation with ggplot2: A Step-by-Step Guide