Linepiece colours in geom_pointpath() about ggh4x

[teunbrand]

More thoughts about this:

• Would be nice to have this makes curves on polar coordinates.
• Can make shape a non-essential aes, then when shape = NA it just prints the gapped path without points.

[teunbrand]

Should now be able to do this:

library(ggplot2)
library(ggh4x)

df <- data.frame(
  x = rep(1:5, 2),
  y = c((2:6)^1.5, (1:5)^2),
  z = rep(LETTERS[1:2], each = 5)
)

ggplot(df, aes(x, y, colour = z)) +
  geom_pointpath() +
  coord_polar()

^{Created on 2020-07-01 by the reprex package (v0.3.0)}