Moving x or y axis together with tick labels to the middle of a single ggplot (no facets)

Question

I made the following plot in Excel:

But then I thought I would make it prettier by using ggplot. I got this far:

If you\'re curious, the da

Answer 1

As alistaire commented it can be done using geom_hline and geom_text as shown below.

df <- data.frame(YearMonth = c(200606,200606,200608,200701,200703,200605),
             person1 = c('Alice','Bob','Alice','Alice','Bob','Alice'),
             person2 = c('Bob','Alice','Bob','Bob','Alice','Bob'),
             Event = c('event1','event2','event3','event3','event2','event4')
)

df$YM <- as.Date(paste0("01",df$YearMonth), format="%d%Y%m")
rangeYM <- range(df$YM)

ggplot()+geom_blank(aes(x= rangeYM, y = c(-1,1))) + labs(x = "", y = "") +
theme(axis.ticks = element_blank()) +
geom_hline(yintercept = 0, col = 'maroon') +
scale_x_date(date_labels = '%b-%y', date_breaks = "month", minor_breaks = NULL) +
scale_y_continuous(minor_breaks = NULL) +
geom_text(aes(x = df$YM, y = 0, label = paste(format(df$YM, "%b-%y")), vjust = 1.5), colour = "#5B7FA3", size = 3.5, fontface = "bold") 

Answer 2

try this,

shift_axis <- function(p, y=0){
  g <- ggplotGrob(p)
  dummy <- data.frame(y=y)
  ax <- g[["grobs"]][g$layout$name == "axis-b"][[1]]
  p + annotation_custom(grid::grobTree(ax, vp = grid::viewport(y=1, height=sum(ax$height))), 
                        ymax=y, ymin=y) +
    geom_hline(aes(yintercept=y), data = dummy) +
    theme(axis.text.x = element_blank(), 
          axis.ticks.x=element_blank())

}

p <- qplot(1:10, 1:10) + theme_bw() 
shift_axis(p, 5)

Answer 3

just to complete baptiste's excellent answer with the equivalent for moving the y axis:

shift_axis_x <- function(p, x=0){
      g <- ggplotGrob(p)
      dummy <- data.frame(x=x)
      ax <- g[["grobs"]][g$layout$name == "axis-l"][[1]]
      p + annotation_custom(grid::grobTree(ax, vp = grid::viewport(x=1, width = sum(ax$height))), 
                            xmax=x, xmin=x) +
        geom_vline(aes(xintercept=x), data = dummy) +
        theme(axis.text.y = element_blank(), 
              axis.ticks.y=element_blank())
    }

Answer 4

I tried to change the theme's axis.text.x,but only can change hjust.
So I think you can delete axis.text.x,then use geom_text() to add.
For example:

test <- data.frame(x=seq(1,5), y=seq(-1,3))
ggplot(data=test, aes(x,y)) +
  geom_line() +
  theme(axis.text.x=element_blank(), axis.ticks.x=element_blank()) +
  geom_text(data=data.frame(x=seq(1,5), y=rep(0,5)), label=seq(1,5), vjust=1.5)

Maybe these codes are useful.