Plotting vertical/horizontal lines that intersect line graph on ggplot

Question

The following code produces the following plot:

time_step <- c(1:5, 1:5)

perceived_signal_slow <- c(1:5, cumsum(1:5))

signal_name <- c("perceived","perceived","perceived","perceived","perceived","accumulated","accumulated","accumulated","accumulated","accumulated")

df <- cbind(perceived_signal_slow, signal_name, time_step)

df <- as.data.frame(df)

df$time_step <- as.numeric(as.character(df$time_step))
df$perceived_signal_slow <- as.numeric(as.character(df$perceived_signal_slow))

ggplot(df, aes(x = time_step, y = signal, colour = signal_name)) +
  geom_line() +
  geom_vline(xintercept = 4, colour = "black", size = 1, alpha = .4) +
  geom_hline(yintercept = 10, colour = "black", size = 1, alpha = .4) +
  geom_hline(yintercept = 4, colour = "black", size = 1, alpha = .4)

However I want to limit the vertical and horizontal lines so that they don't travel any further once they hit the accumulated and perceived lines of my graph. Does anybody know how I could alter my code to do this?

Thanks in advance for the help!

Answer 1

We could use geom_segment:

time_step <- c(1:5, 1:5)

perceived_signal_slow <- c(1:5, cumsum(1:5))

signal_name <- c("perceived","perceived","perceived","perceived","perceived","accumulated","accumulated","accumulated","accumulated","accumulated")

df <- cbind(perceived_signal_slow, signal_name, time_step)

df <- as.data.frame(df)

df$time_step <- as.numeric(as.character(df$time_step))
df$signal <- as.numeric(as.character(df$perceived_signal_slow))

library(ggplot2)
ggplot(df, aes(x = time_step, y = signal, colour = signal_name)) +
  geom_line() +
  geom_segment(x = 4, xend=4, y = -Inf, yend=10, colour = "black", size = 0.2) +
  geom_segment(x= -Inf, xend=4, y = 10, yend = 10, colour = "black", size = 0.2) +
  geom_segment(x= -Inf, xend=4, y = 4, yend = 4, colour = "black", size = 0.2)

This produces: