CODEWITHSUNDEEP
rggplot2visualizationlinegraph
Psychedelique23
Psychedelique23

Reputation: 11

Adding data value labels at both ends of the line graph in ggplot2

I want to illustrate the changes in number of chinese lawyers from 2017 to 2021. I was successful in doing that. But I want to add data value labels at the ends of the line graph to illustrate before and after.

Here's the code :

category<-total_lawyers|>
              pivot_longer(cols =2:6, names_to = "year", values_to = "total" )

graph

    category|>
  ggplot(aes(year, total, group=category,color=category))+
  geom_line(size=1.5)+scale_y_log10()+
  theme_stata()+
  theme(axis.title.y = element_blank(),
        axis.title.x = element_blank())[

enter image description here](https://i.sstatic.net/uuSIS.png)

what I want is to add to add data labels only at both ends.

Upvotes: 0

Views: 46

Answers (1)

bs93
bs93

Reputation: 1316

Besides doing manual annotations as in the comment you can filter your data to just the data you want to highlight and then let ggplot do all the aesthetic mapping for you. Here is an example using the built in mtcars dataset. The dataset is filtered to obtain the minimum or maximum of the value plotted on the x-axis and then those points plotted with an additional geom using that filtered data set:

library(dplyr)
library(ggplot2)

data_to_highlight <-
  mtcars |>
  group_by(cyl) |>
  filter(disp == min(disp) | disp == max(disp))

ggplot()+
  geom_line(data = mtcars,
            aes(x = disp,
                y = mpg,
                color = as.factor(cyl)))+
  geom_point(data = data_to_highlight,
             aes(x = disp,
                 y = mpg,
                 color = as.factor(cyl)))

enter image description here

Note: You also can map the values as text and do some more fun stuff. Here the min/max points of the disp variable is highlighted with points and the corresponding mpg values written in text:

ggplot()+
  geom_line(data = mtcars,
            aes(x = disp,
                y = mpg,
                color = as.factor(cyl)))+
  geom_point(data = data_to_highlight,
             aes(x = disp,
                 y = mpg,
                 color = as.factor(cyl)),
             size = 6, shape = 16)+
  geom_text(data = data_to_highlight,
            aes(x = disp,
                y  = mpg,
                label = mpg),
            size = 2,
            color = "white")

enter image description here

Upvotes: 1

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