How can I add a legend to geom_function in ggplot2

Question

In ggplot, how can I add a legend entry for each of the geom_functions so that the color and linetype are displayed (e.g for fun1 a short dotted red line), along with a custom name that I choose?

ggplot(data = data.frame(x = seq(0, 1, by=0.01)), mapping = aes(x=x)) +
  geom_function(fun = fun1, linetype='11', color='red') +
  geom_function(fun = fun2, color='dark green') +
  geom_function(fun = fun3, linetype='dashed', color='blue')

Vinícius Félix · Answer 1 · 2021-09-04T01:15:50.233

0

You can define them inside aes, here is an example with 3 random functions

Code

ggplot(data = data.frame(x = seq(0, 1, by=0.01)), mapping = aes(x=x)) +
  geom_function(fun = dnorm,aes(col = "fun1"))+
  geom_function(fun = dexp,aes(col = "fun2"))+
  geom_function(fun = sin,aes(col = "fun3"))+
  #Defining the colors
  scale_colour_manual(values = c("red","black","purple"))

Output

edited Sep 04 '21 at 01:15

answered Sep 04 '21 at 01:02

Vinícius Félix

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But what if I want to use specific colors for each function? – An Ignorant Wanderer Sep 04 '21 at 01:08
You can set them with `scale_colour_manual`, for example, `scale_colour_manual(values= c("black","red","purple")` – Vinícius Félix Sep 04 '21 at 01:09
I updated my answer @AnIgnorantWanderer – Vinícius Félix Sep 04 '21 at 01:16
what about the linetype? is it not possible for it to appear in the legend? – An Ignorant Wanderer Sep 04 '21 at 01:31

How can I add a legend to geom_function in ggplot2

1 Answers1

Code

Output