geom_point() and geom_line() for multiple datasets on same graph in ggplot2

Question

I\'m trying to plot three datasets onto the same graph. One dataset should appear on the graph as just a set of unconnected points, whereas the other two should appear as co

Answer 1

The trick is that each layer can have its own dataset. So you have to subset the data to exclude L1=="p1" from the data provided to geom_line:

ggplot(zz, aes(x, y=value, color=L1)) + 
  geom_point() + 
  geom_line(data=zz[zz$L1!="p1", ]) +
  scale_color_manual("Dataset", 
       values = c("p1" = "darkgreen", "p2" = "blue", "p3" = "red"))

Answer 2

You can feed a different dataset into each geom. So you can pass in a dataset excluding p1 into the geom_line layer. Something like this should work:

ggplot(zz, aes(x, value, color = L1)) + 
  geom_point() + 
  geom_line(data = subset(zz, L1 %in% c("p2", "p3")), aes(group = L1)) +
  scale_color_manual("Dataset", values = c("p1" = "darkgreen", "p2" = "blue", "p3" = "red"))