Control transparency of smoother and confidence interval

Question

I\'m refering to this SO question from 2 years ago, with ggplot : Adjust Transparency (alpha) of stat_smooth lines, not just transparency of Confidence Interval

The

Answer 1

This calculates the model twice. But normally that shouldn't be a performance issue.

ggplot(head(airquality, 60), aes(x=Day, y=Temp, color=factor(Month))) +
  geom_point() + 
  geom_ribbon(stat='smooth', method = "lm", se=TRUE, alpha=0.1, 
              aes(color = NULL, group = factor(Month))) +
  geom_line(stat='smooth', method = "lm", alpha=0.3)