Makie parent/children relationships

Specific Domains Visualization
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1

I am new to Makie, so I am still on the learning curve.
I am trying to understand the parent/children relationships.

Assume that I have a Figure with several Axes,
and each Axis contains several Plots.
Assume that I have saved only the Figure object at creation,
but neither the Axis nor the Plot objects.

I learned that I can get all axes as: axs = fig.content
and any of the plots as: plt = axs[i].scene.plots[j]
This is the “children” syntax.

But how can I go backwards from children to parents,
i.e. from a given plt to ax, and from a given ax to fig?

2

Blocks like Axis have a parent field Makie.jl/src/makielayout/blocks.jl at master · MakieOrg/Makie.jl · GitHub

But from plot to Axis there’s no backlink as far as I remember, just from plot to parent Scene. But the Scene doesn’t have a reference to the Axis that owns it.

The Scene graph is the actual relevant structure for rendering, Figure and Blocks are kind of metadata objects parallel to the scene graph.

3

Thank you very much for your informative answer!

It is good to know that axs[i].parent == fig already works.

It would be nice to have a similar mechanism for plots:
plt = axs[i].scene.plots[j]
plt.parent == axs[i]

I don’t know how difficult it would be to implement,
but for the user it would be a very convenient mechanism.

4

It would be fantastic to have some interface for finding parents and children, perhaps even something similar to Matlab’s findobj, which lets you search for eg. all line objects with the color red and a specific user tag. Its very convenient, and I haven’t found any way to replicate that functionality in Makie. Is it theoretically feasible?

5

You can traverse the scene graph, only scene to parent axis doesn’t have a link. But finding all lines that are red wouldn’t be a problem

1 Like
6

While at it, I have just started learning about Scenes.
I understand that these are the fundamental building blocks,
but I find less learning material than for Figures/Axes/Plots etc.

May I have two more questions:

  • Are Scenes mostly for developers and power users,
    but the general user can survive without using them?

  • Parent/children relationships are already there for Scenes.
    Could Figures/Axes/Plots just borrow them?