R: ggplot - plotting a trend line of datapoint with different colors based on group

Question

Assume I have a dataframe df:

Day   Value   Group
1     1       1
2     5       1
3     10      2
4     15      2
5     20      1

I would like to trend a single line on df, x = Day & y = Value, but with each points colored based on Group

Here's a rough illustration for better understanding:

Please advise

Answer 1

You can apply the color= aesthetic to only one layer if needed.

library(ggplot2)
ggplot(dat, aes(Day, Value)) +
  geom_line() +
  geom_point(aes(color = factor(Group)), size = 2)

Data:

dat <- read.table(header=TRUE, text="
Day   Value   Group
1     1       1
2     5       1
3     10      2
4     15      2
5     20      1")