ggplot2 axis label points not displaying as specified

Question

When plotting this data the x and y labels the default label points have multiple decimal places e.g. 0.02999999999999999989 rather than a sensible point like 0.03.

I've tried specifying limits and breaks with scale_y_continuous() function amongst other things.

ggplot(data, aes(x, y, col = z)) + 
    geom_point(size = 2) + 
    scale_y_continuous(limits = c(-0.03, 0.03), breaks = seq(-0.03, 0.03, 0.01))

I am able to change the position of label points by playing with breaks = seq(). In the case of the above code I expect the y-axis to go from -0.03 to 0.03 with label points every 0.01. However they still don't plot exactly as specified and display values with numerous decimal places as in the default plot. e.g I expect a label at 0.01 but get 0.0100000000000000019

Edit: The error is replicated when running M. Viking's code to plot the iris dataset.

You'll need to add an example of your dataset to make your question reproducible. That way others can run your code and see if they can reproduce your problem. :) There are some good hints on how to include your dataset at [this link](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example). The way you describe your issues makes me wonder if your `y` variable is a factor instead of numeric (or something else along those lines). — aosmith, Jul 25 '19 at 23:31
I agree with aosmith, might be something with your data. My `iris` dataset test looks ok `ggplot(iris, aes(Sepal.Length, Sepal.Width/100-.03, col = Petal.Width)) + geom_point(size = 2) + scale_y_continuous(limits = c(-0.03, 0.03), breaks = seq(-0.03, 0.03, 0.01))` — M.Viking, Jul 25 '19 at 23:40
May be that `y` is not numeric in your data. What does `str(data)` show ? — neilfws, Jul 25 '19 at 23:48
I have checked my y is numeric. I get the same error when using M. Viking's code to plot the iris dataset. — CM3, Jul 25 '19 at 23:58
I had no issues with the iris example. Perhaps some option has been set for your local environment. In any case, we can't help further without data. — neilfws, Jul 26 '19 at 01:07

Zhiqiang Wang · Accepted Answer · 2019-07-26T04:04:15.063

Without your data, I assume that you have set options() somewhere in your system, something like: options(digits = 19) although you might not have explicitly done that. To fix this problem, you can either change your default options() or just specify options() before this ggplot:

To reproduce this problem:

options(digits = 19) 

library(tidyverse)
x <- seq(from = -.03, to = 0.03, 0.001) 
y <- (1.01*x) 
z <- y>0
data <- data.frame(y, x,z)

ggplot(data, aes(x, y, col = z)) + 
  geom_point(size = 2) + 
  scale_y_continuous(
    limits = c(-0.03, 0.03), breaks = seq(-0.03, 0.03, 0.01))

To fix the above problem:

options(digits = 5) 
ggplot(data, aes(x, y, col = z)) + 
  geom_point(size = 2) + 
  scale_y_continuous(
    limits = c(-0.03, 0.03), breaks = seq(-0.03, 0.03, 0.01))

ggplot2 axis label points not displaying as specified

1 Answers1