ANOVA
library(broom)
# data for examples
x <- c(44.4, 45.9, 41.9, 53.3, 44.7, 44.1, 50.7, 45.2, 60.1)
covariate...<- sqrt(x) + rnorm(9)
group <- factor(c(rep("A", 4), rep("B", 5)))
my.df <- data.frame(x, group, covariate...)
# Linear regression fit summary, by default
ggplot(my.df, aes(covariate, x)) +
geom_point() +