A 1-D number line/boxplot style chart in R

Question

I am trying to generate a SIMPLE rendering to show the x-range of values as compared to thresholds (red, yellow, green). As inputs, I have lists of numbers representing the number that should be at the leftmost point on the bar, and the number that should be on the rightmost point of the bar:

x1 <- c(44, 73)
boxplot(x1, ylim=c(0,100), horizontal=TRUE, boxwex=0.2)

Ideally, I would be able to produce something that looks like this, with a threshold of red in the background for numbers from [0 to 48), yellow for [48 to 69], and red for (69 to 100]. Ideally there would also be a ggtitle style title.

I have already tried several options with plotly, ggplot2, and stripchart but all fail to generate anything close to my target. Does anyone have any ideas?

Answer 1

You could use the shapes argument in layout for a plotly graph like this:

library(plotly)
library(tibble)
library(purrr)

lims <- local({
  lims <- c(0L, 48L, 69L, 100L)
  tibble(left = head(lims, -1L),
         right = tail(lims, -1L),
         color = c("firebrick", "darkorange", "forestgreen"))
})

shps <- pmap(lims, function(left, right, color) {
  list(
    type = "rect",
    fillcolor = color,
    line = list(width = 0),
    x0 = left,
    x1 = right,
    y0 = 0,
    y1 = 1,
    layer = "below"
  )
})

shps <- c(shps,
          list(
            list(
              type = "rect",
              fillcolor = "#000",
              line = list(color = "#fff", width = 2),
              x0 = 44,
              x1  = 73,
              y0 = .35,
              y1 = .65,
              layer = "below"
            )
          )
)

plot_ly(width = 1000, height = 200) %>% 
  add_text(x = 60, y = .5, text = "Add a Label", textfont = list(color = "#fff")) %>% 
  layout(shapes = shps,
         xaxis = list(ticks = "outside", zeroline = FALSE, showgrid = FALSE),
         yaxis = list(showticklabels = FALSE, zeroline = TRUE, showgrid = FALSE,
                      zerolinecolor = "#000"))