Numerical diagnostics and failures
Validation precedes model construction. It checks identifiers, endpoints, positive flows, terminal fields, physical-link pairing, units, declared transformations, exposure-stock accounting, and route contraction.
Each analysis records:
- route spectral radius, absorption error, bilateral row and column errors, and edge-traffic reconstruction error;
- condition numbers for
NC,NT,F,FM, andFRand their transport systems; - transport solve residuals;
- closure-ladder, inverse-gap, and Hulten-accounting residuals;
- package version and commit, tracked/untracked dirty state, configuration and input hashes, and hashes for every output, including sensitivity output when generated.
- edge-congestion source, input column and scale, and the distribution of active edge-mode elasticities.
The default condition-number ceiling is $10^{12}$ and the identity tolerance is $10^{-10}$. A failed factorization or condition gate stops the run. There is no ridge fallback.
Common failures are actionable:
route kernel is not contractive: absorption shares or flows do not define a terminating route process;exposure stocks differ: node-level outgoing and incoming traffic accounting is inconsistent;physical link ... must have exactly two policy directions: an opposite directed policy row is absent or misidentified;missing ... terminal_id: terminal congestion is active without a declared endpoint;leaves the baseline regular branch: a sensitivity path crosses $e=0$;RSUE input hash mismatch: the external file is not the audited vintage.missing configured edge-congestion column: column-based congestion was requested but the input does not provide complete values;lambda_road is unavailable for input-column edge congestion: use the commonedge_congestion_scalepath instead.