# What is the syntax for vline() in Plots.jl?

There is no documentation and reading the source code didn’t help much.

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vline, scatter, heatmap, etc all just pass through to the plot function. You can imagine it looks like:

vline(args...; kw...) = plot(args...; kw..., seriestype = :vline)


There’s nothing special about them… they’re just a convenience.

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@tbreloff and so if I want to have a bunch of vertical lines at x1, x2 and x3, what is the syntax?

It may be trivial to you, the person who has written the code, but as a user, I still have no clue of what to pass as args. Should it be a list [x1,x2,x3]? How to control the height of the lines? Etc.

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A list [x1,x2,x3] should be fine. If you want to be more precise with how you draw vertical lines, just do it yourself with the normal :path seriestype and separate each line segment with a NaN.

For future reference, the command is:

vline([1,2,3]) # vertical lines at x = 1, 2 and 3.


Notice that you have to pass a 1x1 array if you are interested in a single vertical line (e.g. vline([2])).

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Remember, you can also add more lines using the ! variants of the functions, you don’t have to create them all at once.

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Hello, and what about wanting to have a specific symbol on the x axis at the point of the vertical line?
I did try something like this but it doesn’t work:

plot!([17], seriestype = :vline, xtick="θ")

(and bdw, would it be possible to get it latex-formatted, e.g. for “\bar θ” ?)

I solved for Latex, but not for the tick on the x axis.
The best I could fins is using annotate!(x,0,text()), but that’s a bit ugly, as I can’t go e.g. to -1 in the y axis:

using Plots, StatPlots, DataFrames
pyplot()
df = DataFrame(a = 1:10, b = 10*rand(10), c = 10 * rand(10))
f = Plots.font("DejaVu Sans", 10)
@df df plot(:a, [:b :c], label=["fitted prices" "obs prices"], xtickfont=f, ytickfont=f, legendfont=f, guidefont=f, titlefont=f) # x = :a, y = [:b :c]. Notice this is two columns!
plot!([5], seriestype="vline")
annotate!(5, 0, text("\$\\bar \\delta \$",f, :left))
plot!([7], seriestype="vline")
annotate!(7, 0, text("\$\\bar \\gamma \$",f, :left))


Produces:

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