geom_line 与 R 中 x 轴上的组

Question

I am trying to geom_line plot such that each ID get its own line. However, the current produces vertical lines instead of horizontal lines.

I already looked here and here and here for help but still can't figure out what I am doing wrong.

How can I fix this in R ?

Sample data and code

ID = c("279557", "279557","279557", "279557", "280485", "280485", "280485", "280485")
Var1 = c("1000", "1500", "2000", "3000", "1100", "1700", "2900", "3500")
Var2 = c("3500", "4800", "5500", "6800", "3800", "5800", "6500", "7800")


library(tidyverse)

df = data.frame(ID, Var1, Var2)

        df= df%>% 
          pivot_longer(-c(ID))   

df %>% 
  ggplot(aes(x = ID, y = value, group = ID)) +
  geom_line(size = 1) +
  labs(x = "ID",y = "value")

Output

Desired output

Answer 1

As highlighted in the comments, your data doesn't have an "X" variable. This would typically be something like time or location. Alternatively, manually add one based on the grouped row number. To add the legend, include a mappable value like colour in the aesthetics.

df = df %>% 
  pivot_longer(-c(ID)) %>% 
  group_by(ID) %>% 
  mutate(row = row_number())

df %>% 
  ggplot(aes(x = row, y = value, group = ID, colour = ID)) +
  geom_line(size = 1) +
  labs(x = "ID",y = "value")