Lines on top and bottom of ggplot plot area

Question

I want to add a line on the top and bottom of my plots (bottom line below the x label and axis) created using ggplot2. So far I have added a rectangle around the plot, but I do not want the lines on the sides.

x <- 1:10
y <- rnorm(10,mean = x)
df <- data.frame(x,y)
library(ggplot2)
ggplot(data = df, mapping = aes(x,y)) + geom_point() +
  theme(plot.background = element_rect(size = 1, color = 'blue'))

I hope you guys have a solution.

Answer 1

Will something similar to this work?

x <- 1:10
y <- rnorm(10,mean = x)
df <- data.frame(x,y)
ggplot(data = df, mapping = aes(x,y)) + geom_point() +
    annotate(geom = 'segment', 
             y = Inf, 
             yend = Inf, 
             x = -Inf, 
             xend = Inf, 
             size = 2) +
    theme(axis.line.x = element_line(size = 1))