如何使用 ggplot2 在 R 中连接它们之间的数据表中的点？

Question

I took data from this site CO2 emission

Reshaping

df_reshaped <- data.frame(Countries = df$Country,                           
                          CO2 = c(df$X2018, df$X2017, df$X2016),
                          year = c(rep("X2018", nrow(newdf)),
                                    rep("X2017", nrow(newdf)),
                                    rep("X2016", nrow(newdf))))

# head(df_reshaped)

            Countries     CO2  year
1               China 9663.36 X2018
2       United States 4749.57 X2018
3 European Union (27) 2636.99 X2018
4               India 2400.25 X2018
5           Indonesia 1269.55 X2018
6               Japan 1074.08 X2018

If I try to vizualize data

ggplot(df_reshaped, aes(year, CO2, group=1, col = Countries)) +  geom_point() + geom_line()

I need to connect line each country in correct way.

Answer 1

As @stefan also mentioned in the comments, you should use group = countries . You can use the following code:

library(tidyverse)
ggplot(aes(year, CO2, group = Countries, col = Countries)) +
  geom_point() +
  geom_line()

Output: