rggplot2ggeffects

How to plot different line types for a mixed models output?

I want the plot a mixed models output (2x2 design). Everything is working well, I just want the line for group A to be a dotted one and the line for group B to be a solid one.

Could anybody help?

Here is the code I used:

library(ggeffects)

dput(data)
structure(list(subj = c(1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 3L, 3L, 
3L, 3L, 4L, 4L, 4L, 4L), item = c(1L, 1L, 2L, 2L, 1L, 1L, 2L, 
2L, 1L, 1L, 2L, 2L, 1L, 1L, 2L, 2L), gpR2 = c(0, 83.4, 132, 69.3, 
95.8, 97.4, 36.3, 50.1, 100.2, 40, 87.6, 61.5, 108.8, 47.7, 37.4, 
46.3), lang = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L), levels = c("c", "d"), class = "factor", contrasts = structure(c(1, 
-1), dim = 2:1, dimnames = list(c("c", "d"), NULL))), type = structure(c(2L, 
1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L), levels = c("n", 
"v"), class = "factor", contrasts = structure(c(1, -1), dim = 2:1, dimnames = list(
    c("n", "v"), NULL)))), row.names = c(NA, -16L), class = "data.frame")

mmgpR2 <-lmer(gpR2 ~ lang*type + (1+type|subj) + (1+type*lang|item), data=data)

plot3 = ggpredict(mmgpR2, terms = c("type", "lang"))

plot(plot3, connect.lines = TRUE, colors = "bw") +
     ggeasy::easy_center_title()+
     ggtitle("Nom_vs_Verb") +
     xlab("Type") + ylab("Time")+
     scale_shape_discrete(name="Language",labels=c("Group A","Group B"))+
     easy_all_text_size(15)+
     easy_all_text_color("black")
Solution

  • As a first step, you could map the "group" column of the plot3 data on the linetype aes too, then set your desired linetypes using scale_linetype_manual:

    library(ggplot2)
library(ggeasy)

plot(plot3, connect.lines = TRUE, colors = "bw") +
  aes(linetype = .data[["group"]]) +
  ggeasy::easy_center_title() +
  ggtitle("Nom_vs_Verb") +
  xlab("Type") + ylab("Time") +
  scale_shape_discrete(
    name = "Language",
    labels = c("Group A", "Group B")
  ) +
  easy_all_text_size(15) +
  easy_all_text_color("black") +
  scale_linetype_manual(
    values = c("dotted", "solid"),
    name = "Language",
    labels = c("Group A", "Group B")
  )