ggplot change title and axis labels code example

Example 1: change label x axis ggplot2

theme(
  axis.title = element_text(),         # Change both x and y axis titles
  
  axis.title.x = element_text(),       # Change x axis title only
  axis.title.x.top = element_text(),   # For x axis label on top axis
  
  axis.title.y = element_text(),       # Change y axis title only
  axis.title.y.right = element_text(), # For y axis label on right axis
)

Example 2: labs fill ggplot2

p <- ggplot(df, aes(x=rating, fill=cond)) + 
           geom_density(alpha=.3) + 
           xlab("NEW RATING TITLE") + 
           ylab("NEW DENSITY TITLE")
p <- p + guides(fill=guide_legend(title="New Legend Title"))