Legend positioning for 3d plots in plotly

[briederer]

Disclaimer: This PR is more like a personal aesthetic thing with legends for 3D plots in Plotly.

Personally I got the feeling, that (especially) for 3D-plots with a square size (e.g. size=(400,400)), all the legends that are considered :inner are a bit too high. This is mainly due to the fact that a 3D plot has for most views a large empty space in the corners.

p1=scatter(rand(10,3),rand(10,3),rand(10,3),size=(400,400));
p2=scatter(rand(10,3),rand(10,3),rand(10,3),size=(400,400),legend=:top,title="test");

Before PR:

With PR:

Additionally this resolves the issue that a :top label overlaps with the title (although I would discourage :top labels at all).

Let me know what you think 😄

[codecov]

Codecov Report

Merging #3840 (6e0b085) into master (6fa3dae) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3840      +/-   ##
==========================================
- Coverage   63.23%   63.22%   -0.02%     
==========================================
  Files          28       28              
  Lines        7489     7489              
==========================================
- Hits         4736     4735       -1     
- Misses       2753     2754       +1     

Impacted Files	Coverage Δ
src/recipes.jl	59.49% <0.00%> (-0.11%)	⬇️
src/backends/gr.jl	89.34% <0.00%> (-0.09%)	⬇️
src/colorbars.jl	92.72% <0.00%> (+1.81%)	⬆️

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[BeastyBlacksmith]

wouldn't it would make sense to have it the same for 2D or are there issues? Once putting a 3D figure next to a 2D figure in plotly works it might be difficult to align the legends otherwise

[briederer]

The alignment is indeed a valid point.

Didn't think about that. The problem with also shifting down in the 2D case is that it then takes up too much space of the plot.

My issue is that I really think that the 3D plots are wasting a lot of space by having such a huge separation between the data and the legend. For instance when I want to use a snapshot of 3D plots in a paper they don't look nicely because of the huge amount of whitespace.

I am completely up to rework this PR but in my opinion there should be a way too (manually?) pull the legend closer to the data in the 3d case.

[BeastyBlacksmith]

Both GR and pgfplotsx allow passing a tuple of numbers where 0 is the beginning of the plot and 1 is the end of the plot to place the legend absolutely, maybe that would be an option here?
E.g. plot(1:5, legend = (0.5, 0.5))

[briederer]

Indeed this does also work here.

Thanks for the help.

I changed the PR now such that only the hardcoded numbers in the code are not present anymore.