Merge pull request 'feat/diff_model' (#3) from feat/diff_model into main

Reviewed-on: #3
main
Ruben Seitz 2025-06-13 14:09:32 +02:00
commit bfcb410dab
11 changed files with 238 additions and 89 deletions

1
.gitignore vendored
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@ -24,3 +24,4 @@ docs/site/
# environment.
Manifest.toml
gif

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@ -1,8 +1,8 @@
# This file is machine-generated - editing it directly is not advised
julia_version = "1.11.5"
julia_version = "1.11.4"
manifest_format = "2.0"
project_hash = "0d147eaf78630b05e95b5317275a880443440272"
project_hash = "b5f5f0b50b1e0b7dd05bb93e0b1bb03fea235d53"
[[deps.ADTypes]]
git-tree-sha1 = "e2478490447631aedba0823d4d7a80b2cc8cdb32"
@ -1639,7 +1639,7 @@ version = "3.2.4+0"
[[deps.OpenLibm_jll]]
deps = ["Artifacts", "Libdl"]
uuid = "05823500-19ac-5b8b-9628-191a04bc5112"
version = "0.8.5+0"
version = "0.8.1+4"
[[deps.OpenSSL_jll]]
deps = ["Artifacts", "JLLWrappers", "Libdl"]

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@ -1,4 +1,6 @@
[deps]
DifferentialEquations = "0c46a032-eb83-5123-abaf-570d42b7fbaa"
GLMakie = "e9467ef8-e4e7-5192-8a1a-b1aee30e663a"
Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
Observables = "510215fc-4207-5dde-b226-833fc4488ee2"
Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"

28
scripts/main.jl 100644
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@ -0,0 +1,28 @@
include("../src/gray_scott_solver.jl")
include("../src/visualization.jl")
include("../src/utils/constants.jl")
using Observables
using GLMakie
using .GrayScottSolver
using .Visualization
using .Constants
const N = 128
const dx = 1.0
Du, Dv = Observable(0.16), Observable(0.08)
F, k = Observable(0.060), Observable(0.062)
params_obs = Observable(GSParams(N, dx, Du[], Dv[], F[], k[]))
lift(Du, Dv, F, k) do u, v, f, ki
params_obs[] = GSParams(N, dx, u, v, f, ki)
end
U = ones(N, N)
V = zeros(N, N)
heat_obs = Observable(U)
fig = build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
display(fig)

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@ -1,13 +0,0 @@
include("../src/AnimalFurFHN.jl") # this loads the module code
using .AnimalFurFHN
# include optional visualizer only if needed:
include("../src/visualization.jl")
using .Visualization
N = 100
tspan = (0.0, 1000.0)
sol = AnimalFurFHN.run_simulation(tspan, N)
Visualization.step_through_solution(sol, N)

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@ -1,9 +0,0 @@
# src/AnimalFurFHN.jl
module AnimalFurFHN
include("constants.jl")
include("laplacian.jl")
include("solver.jl")
export run_simulation # Make sure this is here!
end

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@ -0,0 +1,46 @@
module GrayScottSolver
using Observables
include("utils/constants.jl")
include("utils/laplacian.jl")
using .Constants
using .Laplacian
export step!, multi_step!
function step!(U, V, params_obs::Observable; dx=1)
lap_u = laplacian5(U, dx)
lap_v = laplacian5(V, dx)
diff_u = params_obs[].Du
diff_v = params_obs[].Dv
feed_u = params_obs[].F
kill_v = params_obs[].k
u = U[2:end-1, 2:end-1]
v = V[2:end-1, 2:end-1]
uvv = u .* v .* v
u_new = u .+ (diff_u .* lap_u .- uvv .+ feed_u .* (1 .- u))
v_new = v .+ (diff_v .* lap_v .+ uvv .- (feed_u .+ kill_v) .* v)
# Update with new values
U[2:end-1, 2:end-1] .= u_new
V[2:end-1, 2:end-1] .= v_new
# Periodic boundary conditions
U[1, :] .= U[end-1, :]
U[end, :] .= U[2, :]
U[:, 1] .= U[:, end-1]
U[:, end] .= U[:, 2]
V[1, :] .= V[end-1, :]
V[end, :] .= V[2, :]
V[:, 1] .= V[:, end-1]
V[:, end] .= V[:, 2]
# Update heatmap observable
return U
end
function multi_step!(state, n_steps, heat_obs::Observable, params_obs::Observable; dx=1)
for _ in 1:n_steps
heat_obs[] = step!(state[1], state[2], params_obs; dx=1)
end
end
end

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@ -1,61 +0,0 @@
using DifferentialEquations
using Random
using .Constants
"""
fhn(du, u, p:FHNParams, t:)
Implements the spatial dynamics of FitzHugh-Nagumo (fhn). Designed to be
within a larger numerical solver of partial differential equations.
# Arguments
- `du`: output argument which stores the calculated derivatives
- `u`: input vector containing the current state of the system at time t
- `p`: holds all the fixed parameters of the FHN model
- `t`: current time
# Returns
- `du`: calculated derivatives put back into the du array
"""
function fhn!(du, u, p::FHNParams, t = 0)
u_mat = reshape(u[1:p.N^2], p.N, p.N) # activation variable
v_mat = reshape(u[p.N^2+1:end], p.N, p.N) # deactivation variable
Δu = reshape(laplacian(u_mat, p.N, p.dx), p.N, p.N)
Δv = reshape(laplacian(v_mat, p.N, p.dx), p.N, p.N)
fu = p.Du * Δu .+ u_mat .- u_mat .^ 3 ./ 3 .- v_mat
fv = p.Dv * Δv .+ p.ϵ * (u_mat .+ p.a .- p.b .* v_mat)
du .= vcat(vec(fu), vec(fv))
end
"""
run_simulation(tspan::Tuple{Float64,Float64}, N::Int)
solving the ODE and modelling it after FHN
# Arguments
- `tspan`: tuple of two Float64's representing start and end times for simulation
- `N`: size of the N×N grid
# Returns
- `sol`: solved differential equation (ODE)
"""
function run_simulation(tspan::Tuple{Float64,Float64}, N::Int)
# Turing-spot parameters
p = FHNParams(N = N, dx = 1.0, Du = 1e-5, Dv = 1e-3, ϵ = 0.01, a = 0.1, b = 0.5)
# Initial conditions (random noise)
Random.seed!(1234)
# Create two vectors with length N*N with numbers between 0.1 and 0.11
u0 = vec(0.1 .+ 0.01 .* rand(N, N))
v0 = vec(0.1 .+ 0.01 .* rand(N, N))
y0 = vcat(u0, v0)
prob = ODEProblem(fhn!, y0, tspan, p)
sol = solve(prob, BS3(), saveat=1.0) # You can try `Rosenbrock23()` too
return sol
end

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@ -15,6 +15,16 @@ struct FHNParams
new(N, dx, Du, Dv, ϵ, a, b)
end
export FHNParams
struct GSParams
N::Int # grid size
dx::Float64 # grid spacing
Du::Float64 # diffusion rate U
Dv::Float64 # diffusion rate V
F::Float64 # feed rate
k::Float64 # kill rate
end
export FHNParams, GSParams
end # module Constants

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@ -1,3 +1,5 @@
module Laplacian
"""
laplacian(U::Matrix{Float64}, N::Int, h::Float64)
@ -18,3 +20,17 @@ function laplacian(U::Matrix{Float64}, N::Int, h::Float64)
circshift(U, (0, -1)) .+ circshift(U, (0, 1)) .- 4 .* U
return vec(padded) ./ h^2
end
function laplacian5(f, dx)
h2 = dx^2
left = f[2:end-1, 1:end-2]
right = f[2:end-1, 3:end]
down = f[3:end, 2:end-1]
up = f[1:end-2, 2:end-1]
center = f[2:end-1, 2:end-1]
return (left .+ right .+ down .+ up .- 4 .* center) ./ h2
end
export laplacian, laplacian5
end # module Laplacian

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@ -1,6 +1,7 @@
module Visualization
using GLMakie
include("gray_scott_solver.jl")
using GLMakie, Observables, Makie
using .GrayScottSolver
"""
step_through_solution(sol::SolutionType, N::Int)
@ -18,18 +19,146 @@ function step_through_solution(sol, N::Int)
ax = Axis(fig[1, 1])
slider = Slider(fig[2, 1], range=1:length(sol), startvalue=1)
textbox = Textbox(fig[1, 2], placeholder="Feed Rate", validator=Float64)
F = Observable(0.060)
# Initialize heatmap with first time step
u0 = reshape(sol[1][1:N^2], N, N)
heat_obs = Observable(u0)
hmap = heatmap!(ax, heat_obs, colormap=:magma)
on(textbox.stored_string) do s
F[] = parse(Float64, s)
end
# Update heatmap on slider movement
on(slider.value) do i
u = reshape(sol[i][1:N^2], N, N)
heat_obs[] = u
end
display(fig)
end
function coord_to_index(x, y, N)
ix = clamp(round(Int, x), 1, N)
iy = clamp(round(Int, y), 1, N)
return ix, iy
end
function reset!(U, V, heat_obs)
U .= 1.0
V .= 0.0
center = size(U, 1) ÷ 2
radius = 10
U[center-radius:center+radius, center-radius:center+radius] .= 0.50
V[center-radius:center+radius, center-radius:center+radius] .= 0.25
heat_obs[] = copy(U)
end
function param_box!(grid, row, labeltxt, observable::Observable)
Label(grid[row, 1], labeltxt)
box = Textbox(grid[row, 2], validator=Float64, width=50, placeholder=labeltxt, stored_string="$(observable[])")
on(box.stored_string) do s
try
observable[] = parse(Float64, s)
println("changed $labeltxt to $s")
catch
@warn "Invalid input for $labeltxt: $s"
end
end
end
function build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
reset!(U, V, heat_obs)
fig = Figure(size=(800, 800))
gh = GridLayout(fig[1, 1])
ax = Axis(gh[1, 1])
hm = Makie.heatmap!(ax, heat_obs, colormap=:viridis)
deactivate_interaction!(ax, :rectanglezoom)
ax.aspect = DataAspect()
run_label = Observable{String}("Run")
stepsize = Observable(30)
spoint = select_point(ax.scene)
# # Controls
fig[2, 1] = buttongrid = GridLayout(ax.scene, tellwidth=false)
btn_step = Button(buttongrid[1, 1], width=50, label="Step")
btn_start = Button(buttongrid[1, 2], width=50, label=run_label)
btn_reset = Button(buttongrid[1, 3], width=50, label="Reset")
slidergrid = SliderGrid(fig[3, 1], (label="Speed", range=1:1:100, format="{}x", width=350, startvalue=stepsize[]))
speed_slider = slidergrid.sliders[1].value
gh[1, 2] = textboxgrid = GridLayout(ax.scene, tellwidth=false)
rowsize!(gh, 1, Relative(1.0))
param_box!(textboxgrid, 1, "Du", Du)
param_box!(textboxgrid, 2, "Dv", Dv)
param_box!(textboxgrid, 3, "Feed", F)
param_box!(textboxgrid, 4, "kill", k)
# Timer and state for animation
running = Observable(false)
on(running) do r
run_label[] = r ? "Pause" : "Run"
end
on(speed_slider) do s
try
stepsize[] = s
println("Changed stepsize to $s")
catch
@warn "Invalid input for $s"
end
end
# Button Listeners
on(btn_step.clicks) do _
multi_step!((U, V), stepsize[], heat_obs, params_obs)
end
on(btn_start.clicks) do _
running[] = !running[]
end
on(btn_start.clicks) do _
@async while running[]
multi_step!((U, V), stepsize[], heat_obs, params_obs)
sleep(0.0015) # ~20 FPS
end
end
on(btn_reset.clicks) do _
running[] = false
reset!(U, V, heat_obs)
end
on(spoint) do pt
r = 5
if pt === nothing
return
end
x, y = pt
println("params_obs[].N, ", params_obs[].N)
i, j = coord_to_index(x, y, params_obs[].N)
# get corners of square that will get filled with concentration
imin = max(i - r, 1)
imax = min(i + r, params_obs[].N)
jmin = max(j - r, 1)
jmax = min(j + r, params_obs[].N)
# set disbalanced concentration of U and V
U[imin:imax, jmin:jmax] .= 0.5
V[imin:imax, jmin:jmax] .= 0.25
heat_obs[] = copy(U)
end
return fig
end
export step_through_solution, build_ui
end