Missing lines ggplot2 graph-CodePudding

Using the packages ggplot2, dplyr and scales, I make the code the following plot

grafico_4 <- ggplot()  
  ggtitle("Grafico variado")  
  theme(plot.title = element_text(size = 10))  
  theme(panel.background = element_rect(fill='white', colour='white'))  
  theme( axis.line = element_line(colour = "black", size = 0.5))  
  scale_y_discrete(limits = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10"))  
  scale_x_discrete(limits = c("uno", "", "tres", "", "cinco", "", "siete", "", "nueve", ""))  
  geom_hline(yintercept = 5, linetype = "dotted")  
  ylab("")

But why do I get a line between "uno" and "dos" and not between "cinco" and "siete", "siete" and "nueve", and after "nueve"? How do I get the lines to appear?

CodePudding user response：

The limits argument of scale_x_discrete is a place to put possible values of the scale. But it can't show the same value more than once.

So the hackiest possible solution I could think of would be to use different blank strings:

scale_x_discrete(limits = c("uno", "", "tres", " ", "cinco", "   ", "siete", "    ", "nueve"))

This is a terrible solution but I felt compelled to share.

EDIT: Here's a different approach that I think relies on (in my opinion) more typical ggplot2 syntax. One issue I didn't expect is that ggplot2 doesn't seem to want to print the x axis, even if its breaks and limits are specified, until there is a geom that exists in "x-space" -- ie geom_hline won't trigger it, but in this case an invisible point with an x value will.

I think it's more natural to use continuous axes here. In this case I make the labels for the x axis alternate between the text values and blanks using a trick I found here: https://stackoverflow.com/a/25961969/6851825 It turns c("uno", "tres") into c("uno", "", "tres", "").

nums <- c("uno", "tres", "cinco", "siete", "nueve")
ggplot()  
  ggtitle("Grafico variado")  
  theme_classic()  
  theme(plot.title = element_text(size = 10))  
  scale_y_continuous(breaks = 1:10, name = NULL)  
  scale_x_continuous(breaks = 1:10, name = NULL,
                     labels = c(rbind(nums, "")))  
  coord_cartesian(xlim = c(0,11), ylim = c(0,10), expand = 0)  
  geom_hline(yintercept = 5, linetype = "dotted")  
  annotate("point", x = 5, y = 0, alpha = 0)

CodePudding user response：

What you're describing are not limits; they are x-axis labels. If you encode the limits and labels as such, you get the expected output.

library(ggplot2)

ggplot()  
  ggtitle("Grafico variado")  
  theme(plot.title = element_text(size = 10))  
  theme(panel.background = element_rect(fill='white', colour='white'))  
  theme( axis.line = element_line(colour = "black", size = 0.5))  
  scale_y_discrete(limits = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10"))  
  scale_x_discrete(
    limits = factor(1:10),
    labels = c("uno", "", "tres", "", "cinco", "", "siete", "", "nueve", "")
  )  
  geom_hline(yintercept = 5, linetype = "dotted")  
  ylab("")

^{Created on 2021-10-24 by the reprex package (v2.0.1)}