Add option for hiding segment when too short about ggrepel

[slowkow]

Thanks for describing the issue and providing an image!

I agree that the short segments might not be needed. In the past, I removed them automatically if they were too short, but I think I'd prefer your suggestion of a parameter like min.segment.length. I'll consider implementing this in the future, or feel free to make a pull request.

[slowkow]

I implemented the feature you requested in e3c022b:

p <- ggplot(mtcars, aes(wt, mpg, label = rownames(mtcars))) + geom_point()

# Draw all line segments
p + geom_text_repel(
  aes(colour = factor(cyl)), min.segment.length = unit(0, 'lines'))

# Omit short line segments
p + geom_text_repel(
  aes(colour = factor(cyl)), min.segment.length = unit(0.5, 'lines'))

# Omit all line segments
p + geom_text_repel(
  aes(colour = factor(cyl)), segment.color = NA)

Here's a usage example with min.segment.length:

library(ggrepel)

set.seed(42)
ggplot(mtcars) +
  geom_point(aes(wt, mpg)) +
  geom_text_repel(
    aes(
      wt, mpg,
      color = factor(cyl),
      label = rownames(mtcars)
    ),
    size = 5,
    min.segment.length = unit(0.5, 'lines')
  ) +
  scale_color_discrete(name = 'cyl') +
  theme_classic(base_size = 16)

set.seed(42)
ggplot(mtcars) +
  geom_point(aes(wt, mpg)) +
  geom_label_repel(
    aes(
      wt, mpg,
      color = factor(cyl),
      label = rownames(mtcars)
    ),
    size = 4,
    min.segment.length = unit(0.5, 'lines')
  ) +
  scale_color_discrete(name = 'cyl') +
  theme_classic(base_size = 16)