Problem with shared legends when using different geoms and linetypes mixed with colors

[dvalenciaca]

I have 4 plots, each with a different geom, but share the same legend. To group the plots, I use patchwork, but this time I haven't been able to make the legend the way I would like it, as the Sample elements repeat. Any idea?

library(ggplot2)
library(patchwork)

Sample <- c("a", "b")
Time <- c(0,1,2)

df <- expand.grid(Time=Time, Sample = Sample)
df$Value <- c(1,2,3,2,4,6)

p1 <- ggplot(data = df,
             aes(x = Time,
                 y = Value)) +
  geom_point(aes(color = Sample)) +
  geom_line(aes(color = Sample))

p2 <- ggplot(data = df,
             aes(x = Time,
                 y = Value)) +
  geom_function(fun = function(x) x,
                aes(linetype = "Class 1",
                    color = "Class 1")) +
  geom_function(fun = function(x) 2*x,
                aes(linetype = "Class 2",
                    color = "Class 2")) +
  scale_color_manual(name = "Class",
                     values = c("red", "blue")) +
  scale_linetype_manual(name = "Class",
                        values = c(1,2))

p3 <- ggplot(data = df,
             aes(x = Time,
                 y = Value)) +
  geom_point(aes(color = Sample))

p4 <- ggplot(data = df,
             aes(x = Time,
                 y = Value)) +
  geom_point(aes(color = Sample))

plots <- ((p1/p2)|(p3/p4)) +
  plot_annotation(tag_levels = "a") +
  plot_layout(guides = "collect")
plots

I would like to remove some of the sample from the legend

[ltuijnder]

Simply turn off the legends of the figures that you do not want to get shown via theme(legend.position = "none"). See solution for your problem below.

Note that this is a very common problem and so a better place to ask these kinds of questions would be stackOverFlow.

But in either case I hope this helps you.
Cheers

---

library(ggplot2)
library(patchwork)

Sample <- c("a", "b")
Time <- c(0,1,2)

df <- expand.grid(Time=Time, Sample = Sample)
df$Value <- c(1,2,3,2,4,6)

p1 <- ggplot(data = df,
    aes(x = Time,
      y = Value)) +
  geom_point(aes(color = Sample)) +
  geom_line(aes(color = Sample))

p2 <- ggplot(data = df,
    aes(x = Time,
      y = Value)) +
  geom_function(fun = function(x) x,
    aes(linetype = "Class 1",
      color = "Class 1")) +
  geom_function(fun = function(x) 2*x,
    aes(linetype = "Class 2",
      color = "Class 2")) +
  scale_color_manual(name = "Class",
    values = c("red", "blue")) +
  scale_linetype_manual(name = "Class",
    values = c(1,2))

p3 <- ggplot(data = df,
    aes(x = Time,
      y = Value)) +
  geom_point(aes(color = Sample)) +
    theme(legend.position = "none")

p4 <- ggplot(data = df,
    aes(x = Time,
      y = Value)) +
  geom_point(aes(color = Sample))+
    theme(legend.position = "none")

plots <- ((p1/p2)|(p3/p4)) +
  plot_annotation(tag_levels = "a") +
  plot_layout(guides = "collect")
plots

^{Created on 2021-08-31 by the reprex package (v2.0.1)}