Plotting directly

export_vtk and export_pgfplots write a file for another tool to open. Sometimes a plot straight inside the current Julia session is what is wanted instead — Bramble.jl supports that too, through two package extensions that need no code beyond loading a plotting package.

The code on this page is not executed as part of the documentation build — plotting backends are heavy dependencies, and building the documentation should not need to install one. Every call shown here was verified directly against a real backend before being written down.

Makie

Loading any Makie backend — CairoMakie, GLMakie, WGLMakie — makes lines, scatter, heatmap and contour work directly on a VectorElement:

using Bramble, CairoMakie

Ωₕ = mesh(domain(interval(0.0, 1.0)), 33, true)
Wₕ = gridspace(Ωₕ)
uₕ = Rₕ(Wₕ, sin)

lines(uₕ)      # a curve
scatter(uₕ)    # the same points, unconnected

Ω2 = mesh(domain(interval(0.0, 1.0) × interval(0.0, 1.0)), (30, 30), (true, true))
W2 = gridspace(Ω2)
u2 = Rₕ(W2, x -> sin(x[1]) * x[2])

heatmap(u2)    # a flat colour map
contour(u2)    # contour lines

A composite element has no single reading as one curve or one grid — plot each of its components separately:

Vₕ = Wₕ^Val(2)
vₕ = Rₕ(Vₕ, x -> (sin(π * x), cos(π * x)))

lines(components(vₕ)[1])
lines(components(vₕ)[2])

Plots.jl

RecipesBase covers Plots.jl and anything else built on it, the same way:

using Bramble, Plots

plot(uₕ)     # a line by default, matching Rₕ! above
heatmap(u2)  # same 2D field as above

What is not covered

Both extensions are scoped to 1D and 2D. Makie genuinely can render a true 3D volume (Makie.volume) — unlike PGFPlots, which cannot represent one at all — but that path is not wired up here; a 3D VectorElement raises an ArgumentError naming export_vtk as the tool for it, in both extensions.