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Update to DelaunayTriangulation 1.0 (#53)
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DanielVandH committed May 11, 2024
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2 changes: 1 addition & 1 deletion Project.toml
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Expand Up @@ -16,7 +16,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
[compat]
ChunkSplitters = "0.1, 1.0, 2.0"
CommonSolve = "0.2"
DelaunayTriangulation = "0.7, 0.8"
DelaunayTriangulation = "1.0"
PreallocationTools = "0.4"
PrecompileTools = "1.2"
SciMLBase = "1, 2"
Expand Down
6 changes: 3 additions & 3 deletions README.md
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Expand Up @@ -26,19 +26,19 @@ If this package doesn't suit what you need, you may like to review some of the o
As a very quick demonstration, here is how we could solve a diffusion equation with Dirichlet boundary conditions on a square domain using the standard `FVMProblem` formulation; please see the docs for more information.

```julia
using FiniteVolumeMethod, DelaunayTriangulation, CairoMakie, DifferentialEquations
using FiniteVolumeMethod, DelaunayTriangulation, CairoMakie, OrdinaryDiffEq
a, b, c, d = 0.0, 2.0, 0.0, 2.0
nx, ny = 50, 50
tri = triangulate_rectangle(a, b, c, d, nx, ny, single_boundary=true)
mesh = FVMGeometry(tri)
bc = (x, y, t, u, p) -> zero(u)
BCs = BoundaryConditions(mesh, bc, Dirichlet)
f = (x, y) -> y 1.0 ? 50.0 : 0.0
initial_condition = [f(x, y) for (x, y) in each_point(tri)]
initial_condition = [f(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
D = (x, y, t, u, p) -> 1 / 9
final_time = 0.5
prob = FVMProblem(mesh, BCs; diffusion_function=D, initial_condition, final_time)
sol = solve(prob, saveat=0.001)
sol = solve(prob, Tsit5(), saveat=0.001)
u = Observable(sol.u[1])
fig, ax, sc = tricontourf(tri, u, levels=0:5:50, colormap=:matter)
tightlimits!(ax)
Expand Down
9 changes: 7 additions & 2 deletions docs/liveserver.jl
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Expand Up @@ -6,6 +6,11 @@ import LiveServer
withenv("LIVESERVER_ACTIVE" => "true") do
LiveServer.servedocs(;
launch_browser=true,
foldername=joinpath(repo_root, "docs"),
include_dirs=[joinpath(repo_root, "src")],
skip_dirs=[joinpath(repo_root, "docs/src/tutorials"),
joinpath(repo_root, "docs/src/wyos"),
joinpath(repo_root, "docs/src/figures"),
],
)
end

end
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2 changes: 1 addition & 1 deletion docs/src/interface.md
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Expand Up @@ -37,7 +37,7 @@ TriangleProperties

# `BoundaryConditions`: Defining boundary conditions

Once a mesh is defined, you need to associate each part of the boundary with a set of boundary nodes. Since you have a `Triangulation`, the boundary of the mesh already meets the necessary assumptions made by this package about the boundary; these assumptions are simply that they match the specification of a boundary [here in DelaunayTriangulation.jl's docs](https://SciML.github.io/DelaunayTriangulation.jl/dev/boundary_handling/#Boundary-Specification) (for example, the boundary points connect, the boundary is positively oriented, etc.).
Once a mesh is defined, you need to associate each part of the boundary with a set of boundary nodes. Since you have a `Triangulation`, the boundary of the mesh already meets the necessary assumptions made by this package about the boundary; these assumptions are simply that they match the specification of a boundary [here in DelaunayTriangulation.jl's docs](https://juliageometry.github.io/DelaunayTriangulation.jl/dev/manual/boundaries/) (for example, the boundary points connect, the boundary is positively oriented, etc.).

You can specify boundary conditions using `BoundaryConditions`, whose docstring is below; the fields of `BoundaryConditions` are not public API, only this wrapper is.

Expand Down
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Expand Up @@ -29,28 +29,20 @@ tc = DisplayAs.withcontext(:displaysize => (15, 80), :limit => true); #hide
# one part for each boundary condition. This is accomplished
# by providing a single vector for each part of the boundary as follows
# (and as described in DelaunayTriangulation.jl's documentation),
# where we also `refine!` the mesh to get a better mesh.
# where we also `refine!` the mesh to get a better mesh. For the arc,
# we use the `CircularArc` so that the mesh knows that it is triangulating
# a certain arc in that area.
using DelaunayTriangulation, FiniteVolumeMethod, ElasticArrays
using ReferenceTests, Bessels, FastGaussQuadrature, Cubature #src
n = 50

α = π / 4
## The bottom edge
x₁ = [0.0, 1.0]
y₁ = [0.0, 0.0]
## The arc
r₂ = fill(1, n)
θ₂ = LinRange(0, α, n)
x₂ = @. r₂ * cos(θ₂)
y₂ = @. r₂ * sin(θ₂)
## The upper edge
x₃ = [cos(α), 0.0]
y₃ = [sin(α), 0.0]
## Now combine and create the mesh
x = [x₁, x₂, x₃]
y = [y₁, y₂, y₃]
boundary_nodes, points = convert_boundary_points_to_indices(x, y; existing_points=ElasticMatrix{Float64}(undef, 2, 0))
points = [(0.0, 0.0), (1.0, 0.0), (cos(α), sin(α))]
bottom_edge = [1, 2]
arc = CircularArc((1.0, 0.0), (cos(α), sin(α)), (0.0, 0.0))
upper_edge = [3, 1]
boundary_nodes = [bottom_edge, [arc], upper_edge]
tri = triangulate(points; boundary_nodes)
A = get_total_area(tri)
A = get_area(tri)
refine!(tri; max_area=1e-4A)
mesh = FVMGeometry(tri)

Expand All @@ -74,7 +66,7 @@ BCs = BoundaryConditions(mesh, (lower_bc, arc_bc, upper_bc), types)
# specifying the diffusion function as a constant.
f = (x, y) -> 1 - sqrt(x^2 + y^2)
D = (x, y, t, u, p) -> one(u)
initial_condition = [f(x, y) for (x, y) in each_point(tri)]
initial_condition = [f(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
final_time = 0.1
prob = FVMProblem(mesh, BCs; diffusion_function=D, initial_condition, final_time)

Expand All @@ -89,12 +81,18 @@ flux = (x, y, t, α, β, γ, p) -> (-α, -β)
# has the best performance for these problems.
using OrdinaryDiffEq, LinearSolve
sol = solve(prob, TRBDF2(linsolve=KLUFactorization()), saveat=0.01, parallel=Val(false))
ind = findall(DelaunayTriangulation.each_point_index(tri)) do i #hide
!DelaunayTriangulation.has_vertex(tri, i) #hide
end #hide
using Test #hide
@test sol[ind, :] reshape(repeat(initial_condition, length(sol)), :, length(sol))[ind, :] # make sure that missing vertices don't change #hide
sol |> tc #hide

#-
using CairoMakie
fig = Figure(fontsize=38)
for (i, j) in zip(1:3, (1, 6, 11))
local ax
ax = Axis(fig[1, i], width=600, height=600,
xlabel="x", ylabel="y",
title="t = $(sol.t[j])",
Expand Down Expand Up @@ -145,7 +143,7 @@ function exact_solution(x, y, t, A, ζ, f, α) #src
return s #src
end #src
function compare_solutions(sol, tri, α, f) #src
n = DelaunayTriangulation.num_solid_vertices(tri) #src
n = DelaunayTriangulation.num_points(tri) #src
x = zeros(n, length(sol)) #src
y = zeros(n, length(sol)) #src
u = zeros(n, length(sol)) #src
Expand All @@ -162,6 +160,7 @@ end #src
x, y, u = compare_solutions(sol, tri, α, f) #src
fig = Figure(fontsize=64) #src
for i in eachindex(sol) #src
local ax
ax = Axis(fig[1, i], width=600, height=600) #src
tricontourf!(ax, tri, sol.u[i], levels=0:0.01:1, colormap=:matter) #src
ax = Axis(fig[2, i], width=600, height=600) #src
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,7 @@ BCs = BoundaryConditions(mesh, bc, Dirichlet)

# We can now define the actual PDE. We start by defining the initial condition and the diffusion function.
f = (x, y) -> y 1.0 ? 50.0 : 0.0
initial_condition = [f(x, y) for (x, y) in each_point(tri)]
initial_condition = [f(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
D = (x, y, t, u, p) -> 1 / 9

# We can now define the problem:
Expand All @@ -50,17 +50,19 @@ prob.flux_function
# where $(\alpha, \beta, \gamma)$ defines the approximation to $u$ via $u(x, y) = \alpha x + \beta y + \gamma$ so that
# $\grad u(\vb x, t) = (\alpha,\beta)^{\mkern-1.5mu\mathsf{T}}$.

# To now solve the problem, we simply use `solve`. When no algorithm
# is provided, as long as DifferentialEquations is loaded (instead of e.g.
# OrdinaryDiffEq), the algorithm is chosen automatically. Moreover, note that,
# To now solve the problem, we simply use `solve`. Note that,
# in the `solve` call below, multithreading is enabled by default.
using DifferentialEquations
sol = solve(prob, saveat=0.05)
# (If you don't know what algorithm to consider, do `using DifferentialEquations` instead
# and simply call `solve(prob, saveat=0.05)` so that the algorithm is chosen automatically instead
# of using `Tsit5()`.)
using OrdinaryDiffEq
sol = solve(prob, Tsit5(), saveat=0.05)
sol |> tc #hide

# To visualise the solution, we can use `tricontourf!` from Makie.jl.
fig = Figure(fontsize=38)
for (i, j) in zip(1:3, (1, 6, 11))
local ax
ax = Axis(fig[1, i], width=600, height=600,
xlabel="x", ylabel="y",
title="t = $(sol.t[j])",
Expand Down Expand Up @@ -88,7 +90,7 @@ function exact_solution(x, y, t) #src
end #src
end #src
function compare_solutions(sol, tri) #src
n = DelaunayTriangulation.num_solid_vertices(tri) #src
n = DelaunayTriangulation.num_points(tri) #src
x = zeros(n, length(sol)) #src
y = zeros(n, length(sol)) #src
u = zeros(n, length(sol)) #src
Expand All @@ -103,6 +105,7 @@ end #src
x, y, u = compare_solutions(sol, tri) #src
fig = Figure(fontsize=64) #src
for i in eachindex(sol) #src
local ax
ax = Axis(fig[1, i], width=600, height=600) #src
tricontourf!(ax, tri, sol.u[i], levels=0:5:50, colormap=:matter) #src
ax = Axis(fig[2, i], width=600, height=600) #src
Expand Down
40 changes: 15 additions & 25 deletions docs/src/literate_tutorials/diffusion_equation_on_an_annulus.jl
Original file line number Diff line number Diff line change
Expand Up @@ -20,33 +20,19 @@ tc = DisplayAs.withcontext(:displaysize => (15, 80), :limit => true); #hide
# ```math
# u_0(x) = 10\mathrm{e}^{-25\left[\left(x+\frac12\right)^2+\left(y+\frac12\right)^2\right]} - 10\mathrm{e}^{-45\left[\left(x-\frac12\right)^2+\left(y-\frac12\right)^2\right]} - 5\mathrm{e}^{-50\left[\left(x+\frac{3}{10}\right)^2+\left(y+\frac12\right)^2\right]}.
# ```
# The complicated task for this problem is the definition
# of the mesh of the annulus. We need to follow the boundary
# specification from DelaunayTriangulation.jl, discussed
# [here](https://SciML.github.io/DelaunayTriangulation.jl/dev/boundary_handling/).
# In particular, the outer boundary must be counter-clockwise,
# the inner boundary be clockwise, and we need to provide
# the nodes as a `Vector{Vector{Vector{Int}}}`.
# We define this mesh below.
# For the mesh, we use two `CircularArc`s to define the annulus.
using DelaunayTriangulation, FiniteVolumeMethod, CairoMakie
R₁ = 0.2
R₂ = 1.0
θ = collect(LinRange(0, 2π, 100))
θ[end] = 0.0 # get the endpoints to match
x = [
[R₂ .* cos.(θ)], # outer first
[reverse(R₁ .* cos.(θ))] # then inner - reverse to get clockwise orientation
]
y = [
[R₂ .* sin.(θ)], #
[reverse(R₁ .* sin.(θ))]
]
boundary_nodes, points = convert_boundary_points_to_indices(x, y)
R₁, R₂ = 0.2, 1.0
inner = CircularArc((R₁, 0.0), (R₁, 0.0), (0.0, 0.0), positive=false)
outer = CircularArc((R₂, 0.0), (R₂, 0.0), (0.0, 0.0))
boundary_nodes = [[[outer]], [[inner]]]
points = NTuple{2,Float64}[]
tri = triangulate(points; boundary_nodes)
A = get_total_area(tri)
A = get_area(tri)
refine!(tri; max_area=1e-4A)
triplot(tri)


#-
mesh = FVMGeometry(tri)

Expand Down Expand Up @@ -76,7 +62,7 @@ initial_condition_f = (x, y) -> begin
10 * exp(-25 * ((x + 0.5) * (x + 0.5) + (y + 0.5) * (y + 0.5))) - 5 * exp(-50 * ((x + 0.3) * (x + 0.3) + (y + 0.5) * (y + 0.5))) - 10 * exp(-45 * ((x - 0.5) * (x - 0.5) + (y - 0.5) * (y - 0.5)))
end
diffusion_function = (x, y, t, u, p) -> one(u)
initial_condition = [initial_condition_f(x, y) for (x, y) in each_point(tri)]
initial_condition = [initial_condition_f(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
final_time = 2.0
prob = FVMProblem(mesh, BCs;
diffusion_function,
Expand All @@ -91,6 +77,7 @@ sol |> tc #hide
#-
fig = Figure(fontsize=38)
for (i, j) in zip(1:3, (1, 6, 11))
local ax
ax = Axis(fig[1, i], width=600, height=600,
xlabel="x", ylabel="y",
title="t = $(sol.t[j])",
Expand All @@ -115,6 +102,9 @@ using ReferenceTests #src
# apply `jump_and_march`. This is done with `add_ghost_triangles!`.
add_ghost_triangles!(tri)

# (Actually, `tri` already had these ghost triangles,
# but we are just showing how you would add them back in if needed.)

# Now let's interpolate.
x = LinRange(-R₂, R₂, 400)
y = LinRange(-R₂, R₂, 400)
Expand All @@ -124,7 +114,7 @@ last_triangle = Ref((1, 1, 1))
for (j, _y) in enumerate(y)
for (i, _x) in enumerate(x)
T = jump_and_march(tri, (_x, _y), try_points=last_triangle[])
last_triangle[] = indices(T) # used to accelerate jump_and_march, since the points we're looking for are close to each other
last_triangle[] = triangle_vertices(T) # used to accelerate jump_and_march, since the points we're looking for are close to each other
if DelaunayTriangulation.is_ghost_triangle(T) # don't extrapolate
interp_vals[i, j] = NaN
else
Expand Down Expand Up @@ -161,6 +151,6 @@ itp_vals |> tc #hide

#-
fig, ax, sc = contourf(x, y, reshape(itp_vals, length(x), length(y)), colormap=:matter, levels=-10:2:40)
fig
fig
tricontourf!(Axis(fig[1, 2]), tri, u, levels=-10:2:40, colormap=:matter) #src
@test_reference joinpath(@__DIR__, "../figures", "diffusion_equation_on_an_annulus_interpolated_with_naturalneighbours.png") fig #src
Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,7 @@ bn4 = [F, G]
bn = [bn1, bn2, bn3, bn4]
boundary_nodes, points = convert_boundary_points_to_indices(bn)
tri = triangulate(points; boundary_nodes)
refine!(tri; max_area=1e-4get_total_area(tri))
refine!(tri; max_area=1e-4get_area(tri))
triplot(tri)

#-
Expand All @@ -78,7 +78,7 @@ BCs = BoundaryConditions(mesh, (bc1, bc2, bc3, bc4),
# down to $T=40$ at $y=0$.
diffusion_function = (x, y, t, T, p) -> one(T)
f = (x, y) -> 500y + 40
initial_condition = [f(x, y) for (x, y) in each_point(tri)]
initial_condition = [f(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
final_time = Inf
prob = FVMProblem(mesh, BCs;
diffusion_function,
Expand All @@ -98,70 +98,3 @@ fig, ax, sc = tricontourf(tri, sol.u, levels=40:70, axis=(xlabel="x", ylabel="y"
fig
using ReferenceTests #src
@test_reference joinpath(@__DIR__, "../figures", "equilibrium_temperature_distribution_with_mixed_boundary_conditions_and_using_ensembleproblems.png") fig #src

# Let us now suppose we are interested in how the ambient temperature, $T_{\infty}$,
# affects the temperature distribution. In particular, let us ask the following question:
# > What range of $T_{\infty}$ will allow the temperature at $(0.03, 0.03)$ to be between $50$ and $55$?
# To answer this question, we use an `EnsembleProblem` so that we can solve the problem over many
# values of $T_{\infty}$ efficiently. For these new problems, it would be
# a good idea to use a new initial condition given by the solution of the previous problem.
copyto!(prob.initial_condition, sol.u)
using Accessors
T∞_range = LinRange(-100, 100, 101)
ens_prob = EnsembleProblem(steady_prob,
prob_func=(prob, i, repeat) -> let T∞_range = T∞_range, h = h, k = k
_prob =
@set prob.problem.conditions.functions[3].parameters =
(h=h, T∞=T∞_range[i], k=k)
return _prob
end)
esol = solve(ens_prob, DynamicSS(Rosenbrock23()), EnsembleSerial(); trajectories=length(T∞_range))
esol |> tc #hide

# From these results, let us now extract the temperature at $(0.03, 0.03)$. We will use
# NaturalNeighbours.jl for this.
using NaturalNeighbours
itps = [interpolate(tri, esol[i].u) for i in eachindex(esol)];
itp_vals = [itp(0.03, 0.03; method=Sibson()) for itp in itps]
## If you want piecewise linear interpolation, use either method=Triangle()
## or itp_vals = [pl_interpolate(prob, T, sol.u, 0.03, 0.03) for sol in esol], where
## T = jump_and_march(tri, (0.03, 0.03)).
using Test #src
_T = jump_and_march(tri, (0.03, 0.03)) #src
_itp_vals = [pl_interpolate(prob, _T, sol.u, 0.03, 0.03) for sol in esol] #src
@test _itp_vals itp_vals rtol = 1e-4 #src
fig = Figure(fontsize=33)
ax = Axis(fig[1, 1], xlabel=L"T_{\infty}", ylabel=L"T(0.03, 0.03)")
lines!(ax, T∞_range, itp_vals, linewidth=4)
fig

# We see that the temperature at this point seems to increase linearly
# with $T_{\infty}$. Let us find precisely where this curve
# meets $T=50$ and $T=55$.
using NonlinearSolve, DataInterpolations
itp = LinearInterpolation(itp_vals, T∞_range)
rootf = (u, p) -> p.itp(u) - p.τ[]
Tthresh = Ref(50.0)
prob = IntervalNonlinearProblem(rootf, (-100.0, 100.0), (itp=itp, τ=Tthresh))
sol50 = solve(prob, ITP())

#-
Tthresh[] = 55.0
sol55 = solve(prob, ITP())

# So, it seems like the answer to our question is $-11.8 \leq T_{\infty} \leq 55$.
# Here is an an animation of the temperature distribution as $T_{\infty}$ varies.
fig = Figure(fontsize=33)
i = Observable(1)
tt = map(i -> L"T_{\infty} = %$(rpad(round(T∞_range[i], digits=3),5,'0'))", i)
u = map(i -> esol.u[i], i)
ax = Axis(fig[1, 1], xlabel=L"x", ylabel=L"y",
title=tt, titlealign=:left)
tricontourf!(ax, tri, u, levels=40:70, extendlow=:auto, extendhigh=:auto)
tightlimits!(ax)
record(fig, joinpath(@__DIR__, "../figures", "temperature_animation.mp4"), eachindex(esol);
framerate=12) do _i
i[] = _i
end;

# ![Animation of the temperature distribution](../figures/temperature_animation.mp4)
Original file line number Diff line number Diff line change
Expand Up @@ -46,8 +46,8 @@ u_Sp = b
v_Sp = d
u_icf = (x, y) -> 1 - exp(-80 * (x^2 + y^2))
v_icf = (x, y) -> exp(-80 * (x^ 2 + y^2))
u_ic = [u_icf(x, y) for (x, y) in each_point(tri)]
v_ic = [v_icf(x, y) for (x, y) in each_point(tri)]
u_ic = [u_icf(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
v_ic = [v_icf(x, y) for (x, y) in DelaunayTriangulation.each_point(tri)]
u_prob = FVMProblem(mesh, u_BCs;
flux_function=u_q, flux_parameters=u_qp,
source_function=u_S, source_parameters=u_Sp,
Expand All @@ -59,8 +59,8 @@ v_prob = FVMProblem(mesh, v_BCs;
prob = FVMSystem(u_prob, v_prob)

# Now that we have our system, we can solve.
using OrdinaryDiffEq, Sundials
sol = solve(prob, CVODE_BDF(linear_solver=:GMRES), saveat=10.0, parallel=Val(false))
using OrdinaryDiffEq, LinearSolve
sol = solve(prob, TRBDF2(linsolve=KLUFactorization()), saveat=10.0, parallel=Val(false))
sol |> tc #hide

# Here is an animation of the solution, looking only at the $v$ variable.
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,7 @@ ICs = InternalConditions((x, y, t, u, p) -> zero(u),
# one suitable guess is $u(x, y) = 100y$ with $u(1/2, y) = 0$ for $0 \leq y \leq 2/5$;
# in fact, $u(x, y) = 100y$ is the solution of the problem without the internal condition.
# Let us now use this to define our initial condition.
initial_condition = zeros(DelaunayTriangulation.num_solid_vertices(tri))
initial_condition = zeros(DelaunayTriangulation.num_points(tri))
for i in each_solid_vertex(tri)
x, y = get_point(tri, i)
initial_condition[i] = ifelse(x == 1 / 2 && 0 y 2 / 5, 0, 100y)
Expand Down
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Registration pull request created: JuliaRegistries/General/106608

Tip: Release Notes

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"Release notes:" and it will be added to the registry PR, and if TagBot is installed it will also be added to the
release that TagBot creates. i.e.

@JuliaRegistrator register

Release notes:

## Breaking changes

- blah

To add them here just re-invoke and the PR will be updated.

Tagging

After the above pull request is merged, it is recommended that a tag is created on this repository for the registered package version.

This will be done automatically if the Julia TagBot GitHub Action is installed, or can be done manually through the github interface, or via:

git tag -a v1.1.3 -m "<description of version>" 9dc2612219b95eb49b4a81d8cace441f10b6ded4
git push origin v1.1.3

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