CODEWITHSUNDEEP
rggplot2
Nautica
Nautica

Reputation: 2018

Incorrectly displayed linetypes in the legend with ggplot2

I'm following this links example, as I have a similar situation where I'm trying to graph two data frames in the same plot. I'm only interested in changing the linetypes for one of the data frames, which works in the graph, but doesn't display correctly in the legend.

Example dataset:

set.seed(456)
n <- 20
dfr <- data.frame(
  id=rep(1:n, 2),
  group=rep(c("1","2"), each=n), value=c(rnorm(n), rnorm(n, sd=1.1))
)

df_95ci <- data.frame(y_values=c(-1,1)*qnorm(0.95)) 
df_99ci <- data.frame(y_values=c(-1,1)*qnorm(0.99))

require(ggplot2)

Code:

  ggplot(data=dfr, mapping=aes(x=id, y=value)) +
  geom_line(mapping=aes(colour=group)) +
  geom_hline(data= df_95ci, mapping=aes(yintercept=y_values, size= "95% CI"), colour = "orange", linetype="dotdash") +
  geom_hline(data= df_99ci, mapping=aes(yintercept=y_values, size= "99% CI"), colour = "darkred", linetype="dotted") +
  scale_color_hue("Group") +
  scale_size_manual(
    "CI horizontal line", values=rep(1,4),
    guide=guide_legend(override.aes = list(colour=c("orange", "darkred")))
  ) +
  scale_linetype_identity(guide="legend")

Output

As you can see I have two lines with different linetypes, but they're identical in the legend.

Upvotes: 0

Views: 1201

Answers (1)

Sean Lin
Sean Lin

Reputation: 815

Do you want this?

ggplot(data=dfr, mapping=aes(x=id, y=value)) +
    geom_line(mapping=aes(colour=group)) +
    geom_hline(data= df_95ci, mapping=aes(yintercept=y_values, linetype= "95% CI"), 
               colour = "orange", size = 1) +
    geom_hline(data= df_99ci, mapping=aes(yintercept=y_values, linetype= "99% CI"), 
               colour = "darkred", size = 1) +
    scale_linetype_manual(
        "CI horizontal line", values=c("95% CI" = 4, "99% CI" = 3),
        guide=guide_legend(override.aes = list(colour=c("orange", "darkred")))
    )

enter image description here

Upvotes: 2

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