Figure object contains a top-level
Scene and a
GridLayout, as well as a list of layoutables that have been placed into it, like
Wherever you see the old
scene, layout = layoutscene() workflow from MakieLayout, you can imagine that the
Figure takes over the role of both
layout, plus additional conveniences like keeping track of layoutables.
You can create a figure explicitly with the
Figure() function, and set attributes of the underlying scene. The most important one of which is the
f = Figure() f = Figure(resolution = (600, 400))
A figure is also created implicitly when you use simple, non-mutating plotting commands like
lines(), etc. Because these commands also create an axis for the plot to live in and the plot itself, they return a compound object
FigureAxisPlot, which just stores these three parts. To access the figure you can either destructure that object into its three parts or access the figure field directly.
figureaxisplot = scatter(rand(100, 2)) figure = figureaxisplot.figure # destructuring syntax figure, axis, plot = scatter(rand(100, 2)) # you can also ignore components figure, _ = scatter(rand(100, 2))
You can pass arguments to the created figure in a dict-like object to the special
scatter(rand(100, 2), figure = (resolution = (600, 400),))
All layoutables take their parent figure as the first argument, then you can place them in the figure layout via indexing syntax.
f = Figure() ax = f[1, 1] = Axis(f) sl = f[2, 1] = Slider(f)
The indexing syntax of
Figure is implemented to work seamlessly with layouting. If you index into the figure, a
FigurePosition object that stores this indexing operation is created. This object can be used to plot a new axis into a certain layout position in the figure, for example like this:
using GLMakie f = Figure() pos = f[1, 1] scatter(pos, rand(100, 2)) pos2 = f[1, 2] lines(pos2, cumsum(randn(100))) # you don't have to store the position in a variable first, of course heatmap(f[1, 3], randn(10, 10)) f
You can also index further into a
FigurePosition, which creates a
FigureSubpositions you can describe positions in arbitrarily nested grid layouts. Often, a desired plot layout can only be achieved with nesting, and repeatedly indexing makes this easy.
using GLMakie f = Figure() f[1, 1] = Axis(f, title = "I'm not nested") f[1, 2][1, 1] = Axis(f, title = "I'm nested") # plotting into nested positions also works heatmap(f[1, 2][2, 1], randn(20, 20)) f
All nested grid layouts that don't exist yet, but are needed for a nested plotting call, are created in the background automatically.
GridLayouts that are implicitly created when using
FigureSubpositions are not directly available in the return value for further manipulation. You can instead retrieve them after the fact with the
content function, for example, as explained in the following section.
Sometimes users are surprised that indexing into a figure does not retrieve the object placed at that position. This is because the
FigurePosition is needed for plotting, and returning content objects directly would take away that possibility. Furthermore, a
GridLayout can hold multiple objects at the same position, or have partially overlapping content, so it's not well-defined what should be returned given a certain index.
To retrieve objects from a Figure you can instead use indexing plus the
content functions. The
contents function returns a Vector of all objects found at the given
FigurePosition. You can use the
exact = true keyword argument so that the position has to match exactly, otherwise objects contained in that position are also returned.
f = Figure() box = f[1:3, 1:2] = Box(f) ax = f[1, 1] = Axis(f) contents(f[1, 1]) == [ax] contents(f[1:3, 1:2]) == [box, ax] contents(f[1:3, 1:2], exact = true) == [box]
If you use
contents on a
exact keyword only refers to the lowest-level grid layout, all upper levels have to match exactly.
f = Figure() ax = f[1, 1][2, 3] = Axis(f) contents(f[1, 1][2, 3]) == [ax] contents(f[1:2, 1:2][2, 3]) ==  # the upper level has to match exactly
Often, you will expect only one object at a certain position and you want to work directly with it, without retrieving it from the Vector returned by
contents. In that case, use the
content function instead. It works equivalently to
only(contents(pos, exact = true)), so it errors if it can't return exactly one object from an exact given position.
f = Figure() ax = f[1, 1] = Axis(f) contents(f[1, 1]) == [ax] content(f[1, 1]) == ax