How to add legend that overlays marker and line color

[vjd]

is it possible to have a the legend for marker and line overlay on top each other if they follow the same color as in the code and figure below.

I am still not sure exactly on the thinking behind creating the legend from a mapped variable in the dataset. If some one can explain in more detail, I would appreciate it.

dd = DataFrame(id = [1,1,1,1,1,2,2,2,2,2],
               time = [10,20, 30, 40, 50, 10,20, 30, 40, 50],
               dv  = [5.0, 4.0, 3.0, 2.0, 1.0,10.0, 9.0, 8.0, 7.0, 6.0],
               dv2  = [5.0, 4.0, 3.0, 2.0, missing,10.0, 9.0, 8.0, 7.0, missing])
dd[!, :dv2] = coalesce.(dd[!, :dv2], NaN)
palette = ColorSchemes.tab10.colors
color_indices = groupindices(groupby(dd, :id))
fig = Figure(resolution = (1000, 700))
ax1 = fig[1, 1] = Axis(fig, 
  title = "",
  xlabel="Time (min)", 
  ylabel="Concentration (μg/L)")               
scatter!(ax1, 
  dd[!,:time], dd[!,:dv2], 
  color=palette[color_indices])
lines!(ax1, 
  dd[!,:time], dd[!,:dv2],
  color=palette[color_indices])  
fig

basically I want he the legend to be like this (generated by ggplot2 below)

dd = data.frame(id =  c(1,1,1,1,1,2,2,2,2,2),
               time = c(10,20, 30, 40, 50, 10,20, 30, 40, 50),
               dv  =  c(5.0, 4.0, 3.0, 2.0, 1.0,10.0, 9.0, 8.0, 7.0, 6.0),
               dv2  = c(5.0, 4.0, 3.0, 2.0, NA,10.0, 9.0, 8.0, 7.0, NA))
dd %>% 
  ggplot(aes(x = time, y = dv2,color=factor(id)))+
  geom_point() + geom_line()

[sdanisch]

If you use scatterlines it should work like that
Or https://github.com/JuliaPlots/AlgebraOfGraphics.jl, which gives you a whole algebra to combine plot types like that…

[vjd]

Thanks. But what if I have two different arrays, one for lines and one for scatter, both coming from the same if and I want that behavior

[vjd]

scatterlines with the code above only colors the lines and not the markers though

[sdanisch]

Yeah you need to set markercolor separately which is a bit annoying…

But what if I have two different arrays, one for lines and one for scatter

I guess then you may need to use AOG… Or create the legend manually:

https://makie.juliaplots.org/stable/makielayout/legend.html#Creating-A-Legend-From-Elements

[lazarusA]

Example, with manual legends as @sdanisch just mentioned.

Jupyter Notebook Viewer

[vjd]

Thanks, saw that. Could you help me in the context of a data frame and the example above please.

[lazarusA]

the problem with your previous approach is that you are creating two lines or scatter classes at the same time (NaNs in between), and as I can see currently its not possible to get references for both cases… I was expecting to be able to do something like

slegs = scatter!(ax1, 
  dd[!,:time], dd[!,:dv2], 
  color=palette[color_indices])
lineslegs = lines!(ax1, 
  dd[!,:time], dd[!,:dv2], 
  color=palette[color_indices])

and then from there retrieve the references for the labels.
leg = Legend(fig, [[lineslegs[1], slegs[1]], [lineslegs[2], slegs[2]]], ["1", "2"]

and just do

fig[1,2] = leg
This doesn’t work !

otherwise it can be done, but you need to plot each line and scatter independently, as in the example in the link.

BTW. If we wait a little bit, this is pretty easy with AlgebraOfGraphics
http://juliaplots.org/AlgebraOfGraphics.jl/dev/generated/gallery/#Legend-merging

[vjd]

Thanks. Finally, this code below worked for others who are following this thread. Still not ideal as what I was looking for (overlay of marker and line in legend), but will be good for now.

palette = ColorSchemes.tab10.colors
fig = Figure(resolution = (1000, 700))
ax1 = fig[1, 1] = Axis(fig,
           title = "",
           xlabel="Time (min)",
           ylabel="Concentration (μg/L)",
           yscale = log10,
           yminorticksvisible = true, yminorgridvisible = true,
                 yminorticks = IntervalsBetween(8))
#colors = [:red, :blue]
for (i, df) in enumerate(groupby(dd, :id; sort = true))
           scatter!(ax1, df[!, :time], df[!, :dv]; label = "ID: $(df[1, :id])", color = palette[i])
           lines!(ax1, df[!, :time], df[!, :dv]; label = "ID: $(df[1, :id])", color = palette[i])
end
Legend(fig[1, 2], ax1)
fig