Playground

The original MILAMIN was a package you downloaded and edited in MATLAB. This is the browser equivalent: define a model below – geometry, viscosities, boundary conditions, in plain JavaScript – press Run, and the full MilAMin pipeline meshes, assembles, factorizes and renders it locally. Nothing to install; start from a preset and change things.

Preset

Solver threads

Colormap

Colors

Show mesh

Color range

Pressure min / max

Shear stress min / max

idle

Pressure p

Maximum shear stress τ

The model API

A model is a JavaScript function body that ends with return { mesh, mu, bc }:

mesh.boundaries – closed polylines ({ pts, marker }); the marker tags the nodes on that polyline for the bc function. For geometries with open internal interfaces, use explicit mesh.points and mesh.segments ([i, j, marker]) instead – the multilayer preset shows how.
mesh.regions – one seed per enclosed region: [x, y, attribute, maxArea]. The attribute names the material; maxArea sets the local mesh density (smaller = finer). Meshes are capped at ~3 million unknowns (counted as in 2008, the bubble node included). Boundaries may not cross or touch one another: an inclusion must lie inside the box and clear of its neighbours, which is checked before meshing (Triangle would otherwise mesh the slivers where they overlap).
mu(attr) – viscosity for a region attribute.
view – optional initial view [cx, cy, halfWidth]; without it the panels frame the whole model. The automatic colour range is taken from the fields inside the view.
bc(marker, x, y) – Dirichlet velocity [vx, vy] for a boundary node, null to leave it unconstrained or a NaN component for free slip in that direction.

Helpers in scope: rect(x0, y0, x1, y1), circle(cx, cy, r, n), ellipse(cx, cy, rx, ry, n, angleDeg). The code runs in a Web Worker in your browser; Ctrl+Enter runs the model, Stop terminates a runaway one. What you write is kept in your browser: edits to your own model save as you type, while a preset or a shared link you start editing is held apart from it until you press “Save as my model”. The solver is the same MILAMIN pipeline as the million page: 7-node Crouzeix–Raviart triangles from Shewchuk’s Triangle, CHOLMOD’s supernodal Cholesky, Powell–Hestenes pressure recovery.

Limits: linear viscous Stokes only (no gravity body force, no time stepping yet), Dirichlet or free-slip conditions, and one solve per Run – the Folder app shows what a time-stepping loop on the same stack looks like.