voronoiplot

# Makie.voronoiplot — Function.

voronoiplot(x, y, values; kwargs...)
voronoiplot(values; kwargs...)
voronoiplot(x, y; kwargs...)
voronoiplot(positions; kwargs...)
voronoiplot(vorn::VoronoiTessellation; kwargs...)

Generates and plots a Voronoi tessalation from heatmap- or point-like data. The tessellation can also be passed directly as a VoronoiTessellation from DelaunayTriangulation.jl.

Plot type

The plot type alias for the voronoiplot function is Voronoiplot.

source

Examples

A voronoiplot generates a cell for each passed position similar to heatmap, however the cells are not restricted to a rectangular shape. It can be called with point based (like scatter or lines) or heatmap-like inputs.

using CairoMakie
using Random
Random.seed!(1234)


f = Figure(size=(1200, 450))
ax = Axis(f[1, 1])
voronoiplot!(ax, rand(Point2f, 50))

ax = Axis(f[1, 2])
voronoiplot!(ax, rand(10, 10), rand(10, 10), rand(10, 10))
f

┌ Warning: Using non-Float64 coordinates may cause issues. If you run into problems, consider using Float64 coordinates.
└ @ DelaunayTriangulation ~/.julia/packages/DelaunayTriangulation/FJ3Ab/src/algorithms/triangulation/main.jl:133

voronoiplot uses the Voronoi tessellation from DelaunayTriangulation.jl to generate the cells. You can also do this yourself and directly plot the VoronoiTessellation object returned.

using CairoMakie
using DelaunayTriangulation

using Random
Random.seed!(1234)

points = rand(2, 50)
tri = triangulate(points)
vorn = voronoi(tri)
f, ax, tr = voronoiplot(vorn)
f

When considering standard tessellations the unbounded polygons are clipped at a bounding box determined automatically by default, or from a user-provided clipping shape (a rectangle or circle). The automatic bounding box is determined by the bounding box of generators of the tessellation, meaning the provided points, extended out by some factor unbounded_edge_extension_factor (default 0.1) proportional to the lengths of the bounding box's sides.

using CairoMakie
using DelaunayTriangulation

using Random
Random.seed!(1234)

z = LinRange(0, 1, 250) .* exp.(LinRange(0, 16pi, 250) .* im)
f, ax, tr = voronoiplot(real(z), imag(z), unbounded_edge_extension_factor = 0.4, markersize = 7)
f

using CairoMakie
using DelaunayTriangulation

using Random
Random.seed!(1234)

x = LinRange(0, 16pi, 50)
y = sin.(x)
bb = BBox(-1, 16pi + 1, -30, 30) # (xmin, xmax, ymin, ymax)
f, ax, tr = voronoiplot(x, y, show_generators=false,
    clip=bb, color=:white, strokewidth=2)
f

For clipped and centroidal tessellations, there are no unbounded polygons.

using CairoMakie
using DelaunayTriangulation

using Random
Random.seed!(1234)

points = [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 1.0)]
tri = triangulate(points)
refine!(tri; max_area = 0.001)
vorn = voronoi(tri, clip = true)
f, ax, tr = voronoiplot(vorn, show_generators = true, markersize = 13, marker = 'x')
f

using CairoMakie
using DelaunayTriangulation

using Random
Random.seed!(1234)

angles = range(0, 2pi, length = 251)[1:end-1]
x = cos.(angles)
y = sin.(angles)
points = tuple.(x, y)
tri = triangulate(points)
refine!(tri; max_area = 0.001)
vorn = voronoi(tri, clip = true)
smooth_vorn = centroidal_smooth(vorn)
f, ax, tr = voronoiplot(smooth_vorn, show_generators=false)
f

Attributes

alpha

Defaults to 1.0

The alpha value of the colormap or color attribute. Multiple alphas like in plot(alpha=0.2, color=(:red, 0.5), will get multiplied.

clip

Defaults to automatic

Sets the clipping area for the generated polygons which can be a Rect2 (or BBox), Tuple with entries (xmin, xmax, ymin, ymax) or as a Circle. Anything outside the specified area will be removed. If the clip is not set it is automatically determined using unbounded_edge_extension_factor as a Rect.

color

Defaults to automatic

Sets the color of the polygons. If automatic, the polygons will be individually colored according to the colormap.

colormap

Defaults to @inherit colormap :viridis

Sets the colormap that is sampled for numeric colors. PlotUtils.cgrad(...), Makie.Reverse(any_colormap) can be used as well, or any symbol from ColorBrewer or PlotUtils. To see all available color gradients, you can call Makie.available_gradients().

colorrange

Defaults to automatic

The values representing the start and end points of colormap.

colorscale

Defaults to identity

The color transform function. Can be any function, but only works well together with Colorbar for identity, log, log2, log10, sqrt, logit, Makie.pseudolog10 and Makie.Symlog10.

highclip

Defaults to automatic

The color for any value above the colorrange.

lowclip

Defaults to automatic

The color for any value below the colorrange.

marker

Defaults to @inherit marker

Sets the shape of the points.

markercolor

Defaults to @inherit markercolor

Sets the color of the points.

markersize

Defaults to @inherit markersize

Sets the size of the points.

nan_color

Defaults to :transparent

The color for NaN values.

show_generators

Defaults to true

Determines whether to plot the individual generators.

smooth

Defaults to false

No docs available.

strokecolor

Defaults to @inherit patchstrokecolor

Sets the strokecolor of the polygons.

strokewidth

Defaults to 1.0

Sets the width of the polygon stroke.

unbounded_edge_extension_factor

Defaults to 0.1

Sets the extension factor for the unbounded edges, used in DelaunayTriangulation.polygon_bounds.