R ggplot2: odd behaviour of geom_quasirandom when colouring by a factor

I am a regular and happy user of geom_quasirandom from the ggbeeswarm package to make scatterplots where X is a factor. However, I think some recent updates or something I am doing is causing some odd behaviour when colouring dots. The same script was returning a good-looking figure not long ago.

A reproducible example:

library(ggbeeswarm)

# this is correctly placing the dots:
ggplot(mtcars, aes(x=factor(gear), y=drat)) +
  geom_quasirandom()

# but when colouring dots by a factor, some of the dots get ligned up vertically,
# instead of being placed in a violin-like shape
ggplot(mtcars, aes(x=factor(gear), y=drat, color=factor(cyl))) +
  geom_quasirandom()
# (notice particularly the third group of dots, see screenshot below)

# mysteriously, the width argument does not apply to these three dots ligned up vertically
# e.g. command below does not move these dots
ggplot(mtcars, aes(x=factor(gear), y=drat, color=factor(cyl))) +
  geom_quasirandom(width=1)

Can you help?

To color your dots without affecting the positioning you have to explicitly set the group aes so that all points are treated as one group using group=1 or by grouping by the x axis variable only (Would have expected that it does make a difference but looks like that doesn't matter):

library(ggbeeswarm)
#> Loading required package: ggplot2

ggplot(mtcars, aes(x = factor(gear), y = drat, color = factor(cyl), group = 1)) +
  geom_quasirandom()

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ggplot(mtcars, aes(x = factor(gear), y = drat, color = factor(cyl), group = factor(gear))) +
  geom_quasirandom()

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Author of ggbeeswarm here- this behavior is a bug in v0.7.1 and should be fixed in v0.7.2, which I’ve just pushed to CRAN. Please let me know if this remains an issue!