coordinate_system is currently a property of the mesh, so a whole model is either cartesian, cylindrical or spherical. It should live on VolumeSubdomain instead, so that e.g. a spherical pebble and a cylindrical pipe wall can sit in one model, on disconnected Mesh1D blocks coupled by an enclosure.
pebble = F.VolumeSubdomain1D(id=1, borders=[0, 1e-3], material=mat_1,
coordinate_system="spherical")
pipe = F.VolumeSubdomain1D(id=2, borders=[5e-3, 6e-3], material=mat_2,
coordinate_system="cylindrical")Single home, not both: Mesh(coordinate_system=...) becomes a thin deprecated kwarg that emits a DeprecationWarning and applies to subdomains that set nothing, removed after one release.
Why it's a small change
The metric factor never enters the measure — the diffusion term is written r * dot(D*grad(u), grad(v/r)) * dx, so the factors cancel in every zeroth- and first-order term (transient, sources, fluxes, advection carry no r today). Only the diffusion terms need the flag, and they already sit inside per-subdomain loops.
What to change
- A metric-factor helper, e.g.
CoordinateSystem.metric_factor(mesh) returning 1 / r / r**2 (mesh.py:12-40). Each call site becomes w * dot(D*grad(u), grad(v/w)) * dx, correct for cartesian too. Kills three verbatim copies of the same match block.
- Call sites:
HydrogenTransportProblemDiscontinuous (:1632) and HydrogenTransportProblemDG
(:2758). The copies in HydrogenTransportProblem (:911) and ...ChangeVar (:2441) are on the deprecation path — leave them on the deprecated mesh-level flag.
VolumeSubdomain: new kwarg + setter accepting str | CoordinateSystem (volume_subdomain.py:49, forwarded from VolumeSubdomain1D :143). CoordinateSystem is not re-exported in
__init__.py — it should be.- Validation:
check_mesh_dim_coords (mesh.py:228) moves to a per-subdomain check at initialise(). Add: subdomains sharing a conforming Interface must have the same coordinate system (mismatched metrics break flux continuity) — different symmetries connect through disconnected blocks + an enclosure.
- Two blanket guards reject the whole model on the mesh flag and must be re-pointed at the subdomain the quantity/enclosure belongs to: derived quantities :493, enclosures :1714.
coordinate_systemis currently a property of the mesh, so a whole model is either cartesian, cylindrical or spherical. It should live onVolumeSubdomaininstead, so that e.g. a spherical pebble and a cylindrical pipe wall can sit in one model, on disconnectedMesh1Dblocks coupled by an enclosure.Single home, not both:
Mesh(coordinate_system=...)becomes a thin deprecated kwarg that emits aDeprecationWarningand applies to subdomains that set nothing, removed after one release.Why it's a small change
The metric factor never enters the measure — the diffusion term is written
r * dot(D*grad(u), grad(v/r)) * dx, so the factors cancel in every zeroth- and first-order term (transient, sources, fluxes, advection carry nortoday). Only the diffusion terms need the flag, and they already sit inside per-subdomain loops.What to change
CoordinateSystem.metric_factor(mesh)returning1/r/r**2(mesh.py:12-40). Each call site becomesw * dot(D*grad(u), grad(v/w)) * dx, correct for cartesian too. Kills three verbatim copies of the samematchblock.HydrogenTransportProblemDiscontinuous(:1632) andHydrogenTransportProblemDG(:2758). The copies in
HydrogenTransportProblem(:911) and...ChangeVar(:2441) are on the deprecation path — leave them on the deprecated mesh-level flag.VolumeSubdomain: new kwarg + setter acceptingstr | CoordinateSystem(volume_subdomain.py:49, forwarded fromVolumeSubdomain1D:143).CoordinateSystemis not re-exported in__init__.py— it should be.check_mesh_dim_coords(mesh.py:228) moves to a per-subdomain check atinitialise(). Add: subdomains sharing a conformingInterfacemust have the same coordinate system (mismatched metrics break flux continuity) — different symmetries connect through disconnected blocks + an enclosure.