Dashed line around barplot bars

Question

I want to have a dashed line around bar in plotly barplot.

In the following code, I had dash = 'dash' in line attribute but it's not working.

library(plotly)

x <- c('Product A', 'Product B', 'Product C')
y <- c(20, 14, 23)
text <- c('27% market share', '24% market share', '19% market share')
data <- data.frame(x, y, text)

fig <- plot_ly(data, x = ~x, y = ~y, type = 'bar', text = text,
               marker = list(color = 'rgb(158,202,225)',
                             line = list(color = 'rgb(8,48,107)',
                                         width = 1.5, dash = "dash")))
fig <- fig %>% layout(title = "January 2013 Sales Report",
                      xaxis = list(title = ""),
                      yaxis = list(title = ""))

Answer 1

As of right now, line in bar plot doesn't include the argument "dash". However, you can add a dashed line using shapes.

In the code, I've added comments to explain what does what. If there is anything that's unclear, let me know.

First, I calculate where the start and end of each of the bars are in paper space on the x-axis. By default the paper space of the plot, whether x or y axes is equal to 1. You have to divide one by the number of bars to get the start of each bar's 'space.' By default, there is a 10% space added before and after each bar. (You can manually change the space.)

After calculating the start and end of each bar on the x-axis, I build the shapes using the type rect.

When I create the bar plot, I leave out your original call for line within marker.

Check it out:

doThis <- function() {
  # 3 bars, 10% of bar space on each side standard, paper space = 1
  positions <- lapply(0:2, function(k) {
    p1 = k * 1/3 + .1 * 1/3 # left side of bar paper space (x-axis)
    p2 = k * 1/3 + .9 * 1/3 # right side of bar paper space (x-axis)
    c(p1, p2)
  })
  
  lapply(1:3, function(j) {
    list(type = "rect", 
         x0 = positions[[j]][[1]], # as calculated in paper space
         x1 = positions[[j]][[2]],
         y0 = 0, y1 = data$y[j],  # this assumes the data is ordered as plotted
         xref = "paper", yref = "y",
         line = list(color = 'rgb(8,48,107)', # from your original code
                     width = 1.5, dash = "dash"))
  })
}

# your original code, less the call for line
plot_ly(data, x = ~x, y = ~y, type = "bar", text = text, 
        marker = list(color = 'rgb(158, 202, 225)')) %>% 
  layout(title = "January 2013 Sales Report",
         xaxis = list(title = ""), yaxis = list(title = ""),
         shapes = doThis())