How to set separate error bar colors with ggplot2?-CodePudding

I want to manually control the colors of my error bars in a line plot:

col_1<-c(1:4, 1:4)
col_2<-c(25, 30, 28, 28, 35, 36, 39, 40)
er_bar<-c(3, 3, 2, 2, 2,4,4,3)
condition<-c("A","A","A","A", "B","B","B","B")
example<-data.frame(col_1, col_2, er_bar, condition)
example

ggplot(example, aes(col_1, col_2, color=condition))  geom_line(size=0.1) 
  geom_errorbar(aes(ymin=col_2-er_bar, ymax=col_2 er_bar), width=.1, color="blue")  scale_color_manual(values=c("#FF0000", "254117"))

gives me a plot with all the error bars the color blue, as specified. How do I select a separate color for each line?

CodePudding user response：

In order to map the color of your errorbars to the data, you just have to specify color as an argument to the aes function for that geom.

library(ggplot2)

col_1<-c(1:4, 1:4)
col_2<-c(25, 30, 28, 28, 35, 36, 39, 40)
er_bar<-c(3, 3, 2, 2, 2,4,4,3)
condition<-c("A","A","A","A", "B","B","B","B")
example<-data.frame(col_1, col_2, er_bar, condition)
example
#>   col_1 col_2 er_bar condition
#> 1     1    25      3         A
#> 2     2    30      3         A
#> 3     3    28      2         A
#> 4     4    28      2         A
#> 5     1    35      2         B
#> 6     2    36      4         B
#> 7     3    39      4         B
#> 8     4    40      3         B

ggplot(example, aes(col_1, col_2, color=condition))   
  geom_line(size=0.1)  
  geom_errorbar(aes(ymin = col_2-er_bar, ymax = col_2 er_bar, color=condition), width=.1)   
  scale_color_manual(values=c("#FF0000", "254117"))

^{Created on 2021-11-08 by the reprex package (v2.0.1)}

CodePudding user response：

Here is one option, though I'd welcome a cleaner method:

example2<-example %>%
  mutate(testcol = case_when(
    endsWith(condition, "A") ~ "#F88158",
    endsWith(condition, "B") ~ "#0041C2"
  ))

errorbar_colors<-example2$testcol

ggplot(example, aes(col_1, col_2, color=condition))  geom_line(size=0.1) 
  geom_errorbar(aes(ymin=col_2-er_bar, ymax=col_2 er_bar), width=.1, color=errorbar_colors) 
  scale_color_manual(values=c("#FF0000", "254117"))