geom_line with group at x axis in R

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

... I am afraid that does not make any sense ... You need a different x variable, for example time. — tjebo, Nov 14 '21 at 11:26
Thank you. But in your line drawing, how far apart do you want each point to be? That would typically be the x variable. You need both and x and y coordinate. since there are only 2 x coordinates (279557 and 280485), all the points are in a straight vertical line — Joe Erinjeri, Nov 14 '21 at 11:26

score 1 · Accepted Answer · answered Nov 14 '21 at 12:36

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")

geom_line with group at x axis in R

1 Answers1