Overlay vertical line on top of histogram in R using Plotly

Question

I have an histogram like the one below and I want to plot a vertical line of a specific value on top of the histogram.

My code for the histogram is:

library(plotly)
p <- plot_ly(x = ~rnorm(50,mean = 50,sd = 10), type = "histogram")
p

I want to overlay a line on top of the histogram, for example say,

x <- 42

Can anyone help getting this?

I have tried that. I get an error `plot.new has not been called yet` — krish, Jul 28 '17 at 19:47

Marco Sandri · Accepted Answer · 2019-09-03T12:58:36.483

4

library(plotly)
set.seed(1)
p <- plot_ly(x = ~rnorm(50,mean = 50,sd = 10), type = "histogram") %>%
  add_segments(x=42, y=0, xend=42, yend=14, line=list(color="red", width = 4))
p

A different solution (see here for details):

vline <- function(x = 0, color = "red") {
  list(
    type = "line", 
    y0 = 0, 
    y1 = 1, 
    yref = "paper",
    x0 = x, 
    x1 = x, 
    line = list(color = color)
  )
}
p <- plot_ly(x = ~rnorm(50, mean = 50,sd = 10), type = "histogram") %>%
  layout(shapes = list(vline(42)))
p

edited Sep 03 '19 at 12:58

answered Jul 28 '17 at 20:07

Marco Sandri

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Thanks Marco. This works. Do you know if there is there a way to find the max height of the histogram so that I can use that to specify `yend` instead of hard coding it? – krish Jul 31 '17 at 13:44
@krish did you ever find a solution for finding the yend ? – Adrian Nasui Sep 03 '19 at 12:30
@MarcoSandri did you ever find a solution for finding the yend ? – Adrian Nasui Sep 03 '19 at 12:30
thanks @MarcoSandri this works fine, was looking for this solution for 10 hours there isn't much info on this – Adrian Nasui Sep 04 '19 at 08:05

Overlay vertical line on top of histogram in R using Plotly

1 Answers1