Introduction to ggrepel

ggrepel is an R package that extends ggplot2 to automatically position text labels without any overlaps. Check it out at: https://github.com/slowkow/ggrepel

Transcript

1. Introduction to ggrepel github.com/slowkow/ggrepel July 2018 Kamil Slowikowski @slowkow
2. library(ggplot2) ggplot(mtcars) + aes( x = wt, y = mpg, label = rownames(mtcars) ) + geom_point(color = "red") + geom_text() Problem: text placement 2 / 19
3. library(ggrepel) ggplot(mtcars) + aes( x = wt, y = mpg, label = rownames(mtcars) ) + geom_point(color = "red") + geom_text_repel() Solution: ggrepel 3 / 19
4. Much better! 4 / 19
5. other text labels data points edges of the plotting area Repel text labels away from 5 / 19
6. Algorithm N-body physical simulation 6 / 19
7. Install ggrepel from CRAN: install.packages("ggrepel") Installation 9 / 19
8. Example: Volcano Which genes show significant differential expression? Thanks to Stephen Turner for the example data. 10 / 19
9. ggrepel is not always the best choice Sometimes other plots are easier to read Consider other options 11 / 19
10. Don't label too many points! Or else you will end up with @accidental__aRt 12 / 19
11. library(ggrepel) d <- subset( mtcars, wt > 3 & wt < 4 ) # Just label 3 items. d$car <- "" i <- c(2, 3, 16) d$car[i] <- rownames(d)[i] ggplot(d) + aes(wt, mpg, label = car) + geom_point( color = ifelse( d$car != "", "red", "grey50" ) ) + geom_text_repel() Use the empty string "" 13 / 19
12. Learn from examples in the vignette vignette("ggrepel") # <- Run this command in RStudio 14 / 19
13. Please report bugs github.com/slowkow/ggrepel/issues Contributions are very welcome! We have 8 contributors so far. ❓ Stackoverflow is the best place to ask questions. 15 / 19
14. ggplot2 extension gallery 16 / 19
15. Make a ggplot2 extension! ⭐ Extending ggplot2 by Hadley Wickham ⭐ How to make a generic stat in ggplot2 by Elio Campitelli ggplot2 Internals (WOW!) by Brodie Gaslam 17 / 19