passing alpha to geom_mean_lines

[guga31bb]

Describe the bug
alpha doesn't do anything

[mrcaseb]

Wow this is very weird as the alpha actually works but it seems to be necessary to divide it by ten compared to typical values

library(nflplotR)
library(ggplot2)

# inherit top level aesthetics
ggplot(mtcars, aes(x = disp, y = mpg, h_var = mpg, v_var = disp)) +
  geom_point() +
  geom_median_lines() +
  geom_mean_lines(color = "blue", alpha = 0.03) +
  theme_minimal()

^{Created on 2021-10-01 by the reprex package (v2.0.1)}

[mrcaseb]

Here is a comparison between nflplotR and the standard geom_hline in ggplot2

library(nflplotR)
library(ggplot2)

# use same alpha in nflplotr and ggplot
ggplot(mtcars, aes(x = disp, y = mpg)) +
  geom_point() +
  geom_median_lines(aes(h_var = mpg), color = "blue", alpha = 0.1) +
  geom_hline(aes(yintercept = mean(mpg)), color = "red", linetype = 2, alpha = 0.1) +
  theme_minimal()

# use factor ten smaller in nflplotr WTF
ggplot(mtcars, aes(x = disp, y = mpg)) +
  geom_point() +
  geom_median_lines(aes(h_var = mpg), color = "blue", alpha = 0.01) +
  geom_hline(aes(yintercept = mean(mpg)), color = "red", linetype = 2, alpha = 0.1) +
  theme_minimal()

^{Created on 2021-10-01 by the reprex package (v2.0.1)}