R ggplot2: legend should be discrete and not continuous

Question

I have the following data:

benchmark   mispredpenal    IPC     pred
ammp        1               1.0589  2lev
ammp        5               1.0450  2lev
...


        

Answer 1

You want the variable mispredpenal to be a factor in that case:

ggplot(IPC, aes(x = benchmark, y = IPC, group=factor(mispredpenal), colour=factor(mispredpenal))) + 
  geom_point() + geom_line()