Two display fixes for the adaptive grid, from field feedback:
- Equipotential contours showed leaf-sized staircase corners on plane
interiors: the potential is now expanded piecewise-LINEARLY from each
leaf's reconstructed gradient instead of constant-per-leaf, and the
default ADAPTIVE_MAX_CELL_UM drops 2 mm -> 1 mm (interior leaves
beyond that buy almost nothing).
- The raster map now overlays the adaptive mesh: boundaries of coarse
leaves draw in darker copper (fine regions stay plain = fully
resolved), with a legend entry. Uniform-grid runs are unchanged.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Two-point fluxes across coarse-fine faces miss the tangential potential
gradient (offset leaf centers), biasing R ~0.5-2% low. After the first
solve, per-leaf gradients are reconstructed by least squares over face
neighbors and the known tangential term g*delta*Gt moves to the
right-hand side of a re-solve (ADAPTIVE_CORRECTION_PASSES, default 1).
The matrix is unchanged, so the new PreparedSolver reuses the LU
factorization / AMG hierarchy across passes; the corrected currents
satisfy KCL exactly, so the power-balance identity, via currents and
part fluxes all use them consistently (edge power = dV * I_corr).
Measured: strip worst case -1.74% -> -0.028% (1 pass); feature-dense
plate end-to-end -1.1% -> -0.011% at 7.2 s vs 25.9 s uniform (5.58M ->
823k unknowns). Tests tightened accordingly plus a passes-knob test.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
config.ADAPTIVE_CELLS (dialog checkbox "adaptive cells", off by
default; standalone --adaptive) routes run_solve through
fill_resistance/adaptive.py: per-layer balanced leaf grids where every
non-uniform fine cell (electrodes, 1D chain cells, buildup, via-mouth
thickness map) is pinned at the fine size, leaf faces via the
series-half-cell rule, chain links and barrels re-attached by node id,
connectivity restriction and both contact models on the leaf graph via
solver cores extracted for reuse (_equipotential_core, _uniform_core,
_conductance_params, _barrel_links). All fields (V, |J|, power density)
are computed per leaf and expanded to the fine grid, so plots, summary
and dumps are unchanged.
Element sizes: minimum = the grid cell size itself (auto / dialog /
CELL_UM_OVERRIDE); maximum = ADAPTIVE_MAX_CELL_UM (2 mm default);
ADAPTIVE_GUARD sets the clearance a block needs to grow.
Measured end-to-end (feature-dense 120x120 plate, h=50um): 25.9 s ->
5.4 s, 5.58M -> 823k unknowns, R -1.1%. Accuracy documented honestly:
coarse-fine interfaces carry a first-order tangential flux error
biasing R low by ~0.5-2% depending on geometry (worst on narrow
strips); the earlier assumption that linear fields solve exactly on the
leaf graph was wrong - offset centers across size transitions leave an
unpaired residue. Gradient-corrected interface fluxes remain as phase 4
if tighter accuracy per leaf is needed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
janik