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qlroms

The package core. Geometry is the partition and its coordinate systems — charts, the exact atlas, transition maps — and knows nothing about time. Dynamics is what every family compiles into: the shared step(apod) surface and the common operator machinery (ETDRK4, quadratic steps). The dynamodels adapter (QLModel) sits apart: it wraps any fitted qlROM as a dynamodels Model for data assimilation and ntsa. import qlroms loads only the geometry; the intrusive family lives in qlroms.intrusive_qlroms.

Geometry

Name One-liner
charts.fit_clusters(X, K, ...) k-means partition of the snapshots (full / minibatch, clustering space, overlapping assignment).
charts.compute_pod_basis(Xk, r, Mw=None) POD basis of one cluster's centered snapshots, optionally W-weighted.
charts.Chart One chart: centroid + local basis (+ Mw); project_state / recover_state.
charts.QuadROM Family-neutral quadratic member: a Chart with (b, A, B) and the ETDRK4 / discrete step.
atlas.fit_charts(X, K, r, ...) One-call offline geometry: clustering + per-cluster POD + the exact atlas → Atlas.
atlas.build_global_assimilation_basis(...) The shared affine space and the chart ↔ atlas maps (Tgk, dgk, Tkg, dkg).
transitions.TransitionMaps Pairwise chart-to-chart and chart-to-atlas affine maps.

Dynamics

Name One-liner
base.qlROMBase, base.qlROM The compilation of K single-cluster ROMs: step(apod), transition matrix, cluster bookkeeping.
base.free_run(model, x0, n_steps) Closed-loop forecast from a physical state; returns the trajectory and the chart path.
operators.build_etdrk4_coeffs, quadratic_etdrk4_step, quadratic_map_step ETDRK4 coefficients for a reduced linear operator, one quadratic ETDRK4 step, one discrete quadratic map step.

dynamodels adapter

Name One-liner
model.QLModel Any qlROM as a dynamodels Model (observations H z + c, ensembles, time grid).