How to give multiple plots a shared title in Plots.jl

Question

I'm trying to plot several related plots in a grid and I'd like to give a shared title. However, when I use plot(plot1, plot2, title="my title") Plots.jl titles each separate plot with that title. Is there a way to fix this?

I tested the code below with the gr() and plotly() backend. Both have the same behavior.

    using Plots
    using DataFrames

    gr()  # plotly() backend has the same behavior
    
    anscombes_quartet = DataFrame([
    10.0    8.04    10.0    9.14    10.0    7.46    8.0     6.58
    8.0     6.95    8.0     8.14    8.0     6.77    8.0     5.76
    13.0    7.58    13.0    8.74    13.0    12.74   8.0     7.71
    9.0     8.81    9.0     8.77    9.0     7.11    8.0     8.84
    11.0    8.33    11.0    9.26    11.0    7.81    8.0     8.47
    14.0    9.96    14.0    8.10    14.0    8.84    8.0     7.04
    6.0     7.24    6.0     6.13    6.0     6.08    8.0     5.25
    4.0     4.26    4.0     3.10    4.0     5.39    19.0    12.50
    12.0    10.84   12.0    9.13    12.0    8.15    8.0     5.56
    7.0     4.82    7.0     7.26    7.0     6.42    8.0     7.91
    5.0     5.68    5.0     4.74    5.0     5.73    8.0     |6.89 
    ])
    
    rename!(anscombes_quartet, ["x1", "y1", "x2", "y2", "x3", "y3", "x4", "y4"])
    
    plot(
        scatter(anscombes_quartet.x1, anscombes_quartet.y1, label=""),
        scatter(anscombes_quartet.x2, anscombes_quartet.y2, label=""),
        scatter(anscombes_quartet.x3, anscombes_quartet.y3, label=""),
        scatter(anscombes_quartet.x4, anscombes_quartet.y4, label=""),
        title = "Anscombes quartet"
    )

Answer 1

In more recent versions of Plots, this functionality is included in the plot_title keyword which this PR added to Plots v1.19. Documentation is still lacking, so here's an example with the original question:

using Plots #tested v1.29
using DataFrames #tested v1.3.4

gr()

anscombes_quartet = DataFrame([
10.0    8.04    10.0    9.14    10.0    7.46    8.0     6.58
8.0     6.95    8.0     8.14    8.0     6.77    8.0     5.76
13.0    7.58    13.0    8.74    13.0    12.74   8.0     7.71
9.0     8.81    9.0     8.77    9.0     7.11    8.0     8.84
11.0    8.33    11.0    9.26    11.0    7.81    8.0     8.47
14.0    9.96    14.0    8.10    14.0    8.84    8.0     7.04
6.0     7.24    6.0     6.13    6.0     6.08    8.0     5.25
4.0     4.26    4.0     3.10    4.0     5.39    19.0    12.50
12.0    10.84   12.0    9.13    12.0    8.15    8.0     5.56
7.0     4.82    7.0     7.26    7.0     6.42    8.0     7.91
5.0     5.68    5.0     4.74    5.0     5.73    8.0     6.89 
], :auto)

rename!(anscombes_quartet, ["x1", "y1", "x2", "y2", "x3", "y3", "x4", "y4"])

plot(
    scatter(anscombes_quartet.x1, anscombes_quartet.y1, label=""),
    scatter(anscombes_quartet.x2, anscombes_quartet.y2, label=""),
    scatter(anscombes_quartet.x3, anscombes_quartet.y3, label=""),
    scatter(anscombes_quartet.x4, anscombes_quartet.y4, label=""),
    plot_title = "Anscombes quartet"
)

Code Output: