chunkie examples#

An interactive companion to chunkie — a MATLAB package for boundary integral equations in two dimensions. Everything here runs in your browser through numbl: pick a script on the left and click Run.

Every script begins with

mip load --install magland/magland/chunkie

which fetches chunkie on first use.

Geometry#

chunkie represents a curve as a chunker: a panelization into high-order Gauss-Legendre chunks.

• chunkie_ex01_circle.m — chunk up a circle; plot points and normals.
• chunkie_ex02_bymode.m — a star-shaped curve from a Fourier series for the radius.
• chunkie_ex03_starfish.m — the classic starfish.
• chunkie_ex04_chunkerfit.m — fit a smooth curve to sample points (chunkerfit).
• chunkie_ex05_barbell.m — a rounded polygon (chunkerpoly).
• chunkie_ex06_combined.m — transform and merge several curves into one multi-component domain.
• chunkie_ex07_interior.m — find which points lie inside a domain (chunkerinterior).

Solving integral equations#

Each PDE is recast as a boundary integral equation, discretized with chunkermat, solved with GMRES, and evaluated on a grid with chunkerkerneval.

• chunkie_ex00_starfish.m — Helmholtz scattering off a starfish (combined-field representation).
• chunkie_ex08_laplace.m — a Laplace Neumann problem (single-layer with nullspace regularization).
• chunkie_ex09_helmholtz.m — sound-soft Helmholtz scattering off a peanut.
• chunkie_ex10_stokes.m — Stokes flow through a multiply-connected pipe.

How it's deployed#

On every push to main, the workflow in .github/workflows/deploy.yml bundles these files with the numbl browser IDE and publishes the result to GitHub Pages. Edit numbl-project.json to change the title or which file opens first.