4

Is it possible to fill ggplot's geom_dotplot with continuous variables?

library(ggplot2)
ggplot(mtcars, aes(x = mpg, fill = disp)) +
  geom_dotplot()

enter image description here

this should be pretty straightforward, but I've tried messing with the groups aes and no success.

The max I can do is to discretize the disp variable but it is not optimal. 

ggplot(mtcars, aes(x = mpg, fill = factor(disp))) +
  geom_dotplot()

enter image description here

pogibas
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Omar Omeiri
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1 Answers1

6

Good question! You have to set group = variable within aes (where variable is equal to the same column that you're using for fill or color):

library(ggplot2)
ggplot(mtcars, aes(mpg, fill = disp, group = disp)) +
  geom_dotplot()

enter image description here

geom_dotplot in away is just like a histogram. You can't set fill/colour there easily as grouping is done. To make it work you have to set group.

Example using geom_histogram:

ggplot(mtcars, aes(mpg, fill = disp, group = disp)) +
  geom_histogram()

enter image description here

pogibas
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  • Hmm, great! As the new dots are unbinned, I managed to bin them again with `geom_dotplot(method = "histodot", binwidth = 1)`. Thanks! – Omar Omeiri Nov 29 '19 at 23:27