CODEWITHSUNDEEP
rggplot2legend
user2220537
user2220537

Reputation: 13

legend for group of lines in ggplot

I am trying to plot a group of lines and assign one label to these lines in the legend. Here's an example of the data (df2) that I am using.

structure(list(
true = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), 
.Label = c("model1", "model2"), class = "factor"), 
test = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), 
.Label = c("false.model1", "false.model2", "false.model3", "true model"), class = "factor"), 
est.interval = c(0, 5, 5, 7, 7, 10, 10, 11, 11, 0, 2, 2, 3, 3, 0, 2, 2, 4, 4, 0, 2, 2, 3, 3, 4, 4, 0, 7, 7, 10, 10, 13, 13, 0, 4, 4, 5, 5, 0, 5, 5, 6, 6, 7, 7, 9, 9, 0, 2, 2, 3, 3, 4, 4), 
sens = c(1, 1, 0.75, 0.75, 0.5, 0.5, 0.25, 0.25, 0, 1, 1, 0.25, 0.25, 0, 1, 1, 0.5, 0.5, 0, 1, 1, 0.5, 0.5, 0.25, 0.25, 0, 1, 1, 0.75, 0.75, 0.25, 0.25, 0, 1, 1, 0.5, 0.5, 0, 1, 1, 0.75, 0.75, 0.5, 0.5, 0.25, 0.25, 0, 1, 1, 0.5, 0.5, 0.25, 0.25, 0)), 
.Names = c("true", "test", "est.interval", "sens"), 
class = "data.frame")

And here I plot the curves using ggplot. 

ggplot(df2, aes(x=est.interval, y=sens, color=test)) +
    ylim(0,1) +
    geom_line(size = 0.6) +
    facet_wrap(~true, nrow=1) +
    scale_colour_manual(values=c(rep('#CCCCCC', 3), "#000000"), name="Estimation Model") + 
    guides(color=guide_legend(keywidth = 3, keyheight = 1))

I'd like to have the three grey "false.model" curves separately visible on the plot, but in the legend I just want one "false models" entry beside one grey line. Any thoughts on how to do this?

Upvotes: 1

Views: 2392

Answers (1)

MrFlick
MrFlick

Reputation: 206167

I had a problem with your dput. It seemed to be missing rownames which made it an invalid data.frame. Here a corrected dump

df2 <- structure(list(true = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("model1", 
"model2"), class = "factor"), test = structure(c(1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 
2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L), .Label = c("false.model1", "false.model2", "false.model3", 
"true model"), class = "factor"), est.interval = c(0, 5, 5, 7, 
7, 10, 10, 11, 11, 0, 2, 2, 3, 3, 0, 2, 2, 4, 4, 0, 2, 2, 3, 
3, 4, 4, 0, 7, 7, 10, 10, 13, 13, 0, 4, 4, 5, 5, 0, 5, 5, 6, 
6, 7, 7, 9, 9, 0, 2, 2, 3, 3, 4, 4), sens = c(1, 1, 0.75, 0.75, 
0.5, 0.5, 0.25, 0.25, 0, 1, 1, 0.25, 0.25, 0, 1, 1, 0.5, 0.5, 
0, 1, 1, 0.5, 0.5, 0.25, 0.25, 0, 1, 1, 0.75, 0.75, 0.25, 0.25, 
0, 1, 1, 0.5, 0.5, 0, 1, 1, 0.75, 0.75, 0.5, 0.5, 0.25, 0.25, 
0, 1, 1, 0.5, 0.5, 0.25, 0.25, 0)), .Names = c("true", "test", 
"est.interval", "sens"), row.names = c(NA, -54L), class = "data.frame")

The easiest thing to do would be to create a new factor that you can use for the coloring. For example

df2$testcol<-factor(ifelse(df2$test=="true model",1,2), 
   levels=1:2,
   labels=c("True Model","False Model"))

Now all the false models will share a common value. Then you can do

ggplot(df2, aes(x=est.interval, y=sens, group=test, colour=testcol)) +
    ylim(0,1) +
    geom_line(size = 0.6) +
    facet_wrap(~true, nrow=1) +
    scale_colour_manual(values=c("True Model"='#CC0000', 
        "False Model"="#999999"), name="Estimation Model") + 
    guides(color=guide_legend(keywidth = 3, keyheight = 1))

to get

enter image description here

Upvotes: 1

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