Adding horizontal lines in the plot of a step function-CodePudding

I attach graphic, image.jpg, in which I want to draw the line y=0 for x<3 and the line y=1 for x>=8, i.e. the result would be image2.jpg.

These are the instructions for image.jpg.

df <- data.frame(x=Asignaturas, y=solF)
df$xend <- c(df$x[2:nrow(df)],NA)
df$yend <- df$y
p <- (ggplot(df, aes(x=x, y=y, xend=xend, yend=yend))  
geom_vline(aes(xintercept=x), linetype=2,color="grey")  
geom_point()   # Solid points to left
geom_point(aes(x=xend, y=y), shape=1)   # Open points to right
geom_segment()   # Horizontal line
geom_text(aes(label = paste0(solF,''),vjust = -0.5), color = "black")  
ylab("Función de distribucción")   
xlab("Asignaturas"))
p

Does anyone know how to do it?

Thanks

enter image description here

CodePudding user response：

An option using base R.

plot(df$x, df$y, xlim=c(2.5, max(df$x)   .5), ylim=c(0, 1.075), pch=19)
points(df$x   1, df$y, pch=1)
segments(df$x, df$y, df$x   1)
text(df$x, df$y   .05, df$y)
sapply(0:1, \(x) lines(2:3   x*6, rep(x, 2), col='red'))

Or just

plot(df$x, df$y, type='s', xlim=c(2.5, max(df$x)   .5), ylim=c(0, 1.075))
text(df$x, df$y   .05, df$y)
sapply(0:1, \(x) lines(2:3   x*6, rep(x, 2), col='red'))

Data:

df <- structure(list(y = c(0, 0.14, 0.31, 0.48, 0.67, 0.82, 1), x = c(2, 
3, 4, 5, 6, 7, 8)), class = "data.frame", row.names = c(NA, -7L
))

CodePudding user response：

If you want to stick with ggplot2, the geom_segment() will give what you're looking for. Make a data.frame of the parameters and then add the geom_segment().

extraLines <- data.frame(x = c(-Inf, max(df$x)), xend = c(min(df$x), Inf), y = c(2, max(df$y)), yend = c(2, max(df$y)))

p  
  geom_segment(data = extraLines, aes(x = x, xend = xend, y = y, yend = yend), colour = "red")  
  geom_point(data = filter(extraLines, x > 0), aes(x = x, y=y), colour = "red")   
  geom_point(data = filter(extraLines, x < max(df$x)), aes(x=xend, y=y), shape = 1, colour = "red")