带有geom_text ggplot2的标签

Question

Hy guys, I have a df and with this code

ggplot(logger) + geom_line(aes(Date.time, T, group=ID, colour=ID))+
  ggtitle("Temperature in piezometers") +
  xlab("Time") +
  ylab("Temperature")

I can made this graph:

That's fine, but is there a way to add ID labels directly on the graph just next to the end of the lines? I mean, replace the legend with a direct on graph labeling. I guess it should be done with geom_text function, but all my attempts failed.

Answer 1

Create a new data.frame with the positions of the labels

library(ggplot2)
set.seed(12345)
dataset <- do.call(
  rbind, 
  lapply(seq_len(5), function(i){
    data.frame(
      ID = i,
      Time = 1:100,
      Temp = as.vector(arima.sim(model = list(ar = .8), n = 100))
    )
  }) 
)
dataset$ID <- factor(dataset$ID)
Right <- subset(dataset, Time == max(Time))
ggplot(dataset, aes(x = Time, y = Temp, colour = ID)) + geom_line() + geom_text(data = Right, aes(label = ID))

Answer 2

You can also use annotate . This gives you a bit more flexibility, though you would have to specify where you want the annotation to be.

See documentation: http://docs.ggplot2.org/current/annotate.html