no able to produce a legend

[Fra]

Hello guys, I am not able to visualise a legend using the following code, does anyone know why?

dot_graph = ggplot()+
  geom_point(data = table_3, aes(x = time, y=control), shape = "triangle", color = "blue")+
  geom_point(data = table_3, aes(x = time, y=temp_20_pH_7.67), shape = "circle", color = "green")+
  geom_point(data = table_3, aes(x = time, y=temp_23_pH_8.1), shape = "square", color = "limegreen")+
  geom_point(data = table_3, aes(x = time, y=temp_23_ph_7.67), shape = "cross", color = "mediumblue")+
  theme(legend.position = "top")+
  xlab('time')+
  ylab('% of settlement')+
  scale_x_discrete(limits = c(0,20,40,60,80,100,120))+
  scale_y_discrete(limits = c(0,20,40,60,80,100))+
  theme_classic()+
  theme(plot.margin = unit(c(2,2,2,2),"cm"))+
  expand_limits(y=c(0,100))

Many thanks!

[andresrcs]

You have to map your variables to an aesthetics (shape, color, etc.) to get an automatic legend, this could be achieved by reshaping your dataframe to a long format before plotting or you could manually add some scales to get a legend.

We could give you more specific help if you provide a reproducible example, could you please turn this into a self-contained REPRoducible EXample (reprex)? A reprex makes it much easier for others to understand your issue and figure out how to help.

If you've never heard of a reprex before, you might want to start by reading this FAQ:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

[Fra]

Thanks Andres, here it is, I've inserted (-) between each header of each column :
time - control - temp_20_pH_7.67 - temp_23_pH_8.1 - temp_23_ph_7.67
10 10 18 3 10
20 20 30 5 10
30 25 40 8 13
40 38 43 10 15
50 40 48 13 25
60 40 48 13 30

[andresrcs]

Please read the link I gave you, that is not a copy/paste friendly format, is actually pretty easy to properly share sample data, give it a try.

[Fra]

here it is:

#libraries
library(sqldf)
library(ggplot2)
library(ggpubr)
library(dplyr)
library(tibble)

#the dataframe
data.frame(
time = c(10, 20, 30, 40, 50),
control = c(10, 20, 25, 38, 40),
temp_20_pH_7.67 = c(18, 30, 40, 43, 48),
temp_23_pH_8.1 = c(3, 5, 8, 10, 13),
temp_23_ph_7.67 = c(10, 10, 13, 15, 25)
)

#the command
dot_graph = ggplot()+
geom_point(data = table_3, aes(x = time, y=control), shape = "triangle", color = "blue")+
geom_point(data = table_3, aes(x = time, y=temp_20_pH_7.67), shape = "circle", color = "green")+
geom_point(data = table_3, aes(x = time, y=temp_23_pH_8.1), shape = "square", color = "limegreen")+
geom_point(data = table_3, aes(x = time, y=temp_23_ph_7.67), shape = "cross", color = "mediumblue")+
theme(legend.position = "top")+
xlab('time')+
ylab('% of settlement')+
scale_x_discrete(limits = c(0,20,40,60,80,100,120))+
scale_y_discrete(limits = c(0,20,40,60,80,100))+
theme_classic()+
theme(plot.margin = unit(c(2,2,2,2),"cm"))+
expand_limits(y=c(0,100))+
ggtitle("Larvae settlement time in each treatment")+
theme(plot.title = element_text(hjust=0.5))

[andresrcs]

That was very close to a proper reprex, you just need to integrate all the parts and narrow down your code to the problematic part, take a look at the way I'm sharing my solution.

library(ggplot2)
library(dplyr)
library(tidyr)

table_3 <- data.frame(
    time = c(10, 20, 30, 40, 50),
    control = c(10, 20, 25, 38, 40),
    temp_20_pH_7.67 = c(18, 30, 40, 43, 48),
    temp_23_pH_8.1 = c(3, 5, 8, 10, 13),
    temp_23_ph_7.67 = c(10, 10, 13, 15, 25)
)

table_3 %>% 
    gather(type, settlement, -time) %>% 
    ggplot(aes(x = time, y=settlement, shape = type, color = type))+
    geom_point()+
    labs(title = "Larvae settlement time in each treatment",
         x = 'Time',
         y = '% of settlement') +
    theme_classic()+
    expand_limits(y=c(0,100))+
    theme(plot.title = element_text(hjust=0.5))

^{Created on 2019-02-22 by the reprex package (v0.2.1)}

[Fra]

Thanks Andres, it looks perfect!

[andresrcs]

If your question's been answered (even by you!), would you mind choosing a solution? It helps other people see which questions still need help, or find solutions if they have similar problems. Here’s how to do it:

FAQ: How do I mark a solution?

If your question has been answered, don't forget to mark the solution! How do I mark a solution? Find the reply you want to mark as the solution and look for the row of small gray icons at the bottom of that reply. Click the one that looks like a box with a checkmark in it: [image] Hovering over the mark solution button shows the label, "Select if this reply solves the problem". If you don't see the mark solution button, try clicking the three dots button ( ••• ) to expand the full set of options. When a solution is chosen, the icon turns green and the hover label changes to: "Unselect if this reply no longer solves the problem". Success! [solution_reply_author] …