library(ggpmisc)
data <- mpg
table(data$class)
data$class[mpg$class=="2seater"] <- c(rep("2seater", 1), rep("compact", 4))
formula <- y ~ x + I(x^2)
ggplot(data, aes(x = displ, y = hwy, color = class)) +
geom_point() +
geom_smooth(method = "lm", formula = formula) +
ggpmisc::stat_poly_eq(aes(label = paste(stat(eq.label), stat(adj.rr.label), sep = "*\", \"*")),
formula = formula, parse = TRUE)
The above code will produce a plot without the formula and r-squared labels. And will give this warning:
Warning message:
Computation failed in `stat_poly_eq()`:
argument "x" is missing, with no default
The problem stems from the fact that the 2seater
color group only has one data point. It isn't enough. But then it should at least output labels for the other groups?