Customizing Plot Symbols and Legends in R Base Plots

Understanding the Behavior of scale_color_discrete(drop = TRUE) in ggplot2: A Guide to Troubleshooting Missing Values

Creating Informative Scatterplots: Colored by Date with Legend

Adding Boxes for NA Values in ggplot2 Legends for Continuous Maps

Centering Values in Stacked Bar Plots with ggplot: A Comprehensive Guide

Missing Legends in ggplot2 and geom_line