common ggplot needs.R

# base plot
ggplot(mtcars, aes(x = mpg, y = hp)) + 
    geom_point()

# Ensure that the legend is single line (e.g. at the bottom)
# I need to use guide_legend() because it is discrete
# use guide_colorbar() for continuous

ggplot(mtcars, aes(x = mpg, y = hp, color = cyl)) + 
    geom_point() + 
    guides(color = guide_legend(nrow = 1)) + 
    theme(legend.position = "bottom")
    
    
# Control the distance between the data and the panel border
ggplot(mtcars, aes(x = mpg, y = hp)) + 
    geom_point() +
    scale_y_continuous(expand = expansion(mult = c(0.1, 0.2)))


# Use colours in the subtitle
library(ggtext)
library(MetBrewer)
# met.brewer("Cassatt1", 3) %>% as.vector()
ggplot(mtcars, aes(x = mpg, y = hp, color = as.factor(cyl))) + 
    geom_point() + 
    scale_color_met_d(name = "Cassatt1") +
    labs(y = "Horsepower", x = "Miles per gallon", title = "Figure Title",
         subtitle = "Comparing the <span style = color:#B1615C>4 Cylinder</span>, <span style = color:#E3ABA7>6 Cylinder</span> to <span style = color:#8282AA>8 Cylinder</span>") +
    theme(plot.subtitle = ggtext::element_markdown(size = 15),
         legend.position = "none")