creating a common legend for bar plot and line
问题 I'm very new to R so I apologise in advance if this is a very basic question. I'm trying to plot a graph showing discharge and suspended sediment load (SSL). However, I want to make it clear that the bar plot represents discharge, and the line graph represents SSL. I had two ideas: color the label for discharge and SSL to correspond to the bar graph and line graph respectively, so the reader intuitively knows which one belongs to which. but ggplot2 doesn't allow me to do this because it'll