plotting the whole data within each facet using facet_wrap and ggplot2

Question

I am trying to plot line graphs for and facet_wrap for each dataset. What I would love to have is in light grey, transparent or something, all datasets in the b

Answer 1

Here's another approach:

First add a new column identical to id:

df$id2 <- df$id

Then add another geom_line based on the df without the original id column:

ggplot(df, aes(x,y, group=id)) + 
  geom_line(data=df[,2:4], aes(x=x, y=y, group=id2), colour="grey") +
  geom_line() + 
  facet_wrap(~ id)