API reference

Aperta is organized as a flat collection of algorithm modules. Each module focuses on one phase of the six-phase accessibility workflow and operates on plain numpy / pandas / networkx inputs without any framework scaffold.

At a glance

Module	Purpose
od_pairs	Tiered OD pair structures + builders, including cross-modal alignment.
routing	Shortest paths on networkx graphs via scipy.sparse.csgraph.dijkstra: tiered OD routing, per-edge / per-node feature aggregation along realized paths, intrazonal-cost flooring.
accessibility	Cumulative-opportunity, gravity, nearest-k metrics. Per-node or per-cell output depending on input ODM class.
utility	Linear utility specifications and the routing-+-endpoint pipeline for utility-based costs; consumed by gravity with an exp decay for logsum accessibility.
overhead	First/last-mile overheads on geo-keyed cost ODMs, with helpers for zone-tier last-mile aggregation.
traffic_flows	Traffic-volume estimation via cost-weighted nested-node sampling.
calibration	OLS calibration of per-edge weights against observed travel times; bearing-aware traffic-counter snapping + counter-fit evaluation for flow calibration.
network_processing	Network helpers — sampled edge betweenness, node/edge attribute aggregation, feature snapping.
network_snap	Snap-target resolution — snap_to_network_nodes (point-to-node match, optionally two-tier with a priority set), insert_projected_nodes (virtual-node insertion).
routing_prep	Mode-aware graph preparation — prepare_network, compute_snap_eligibility, PreparedGraph.
geo_processing	Geometry helpers — H3 grids, line bearings, KDTree-based buffer aggregations, raster sampling, Copernicus GLO-30 DEM download (fetch_copernicus_dem requires aperta[topo]).
geo_mapping	Spatial-join wrappers between points, polygons, and filtered lines.
data_processing	Tabular helpers — dedup indices after a spatial join, add straight-line distance, weighted mean per group.
visualization	Plot helpers — choropleth panels, multi-panel comparisons, per-edge LineCollection rendering, styled colorbars.
errors	aperta-specific exception types.

Core OD + routing

• aperta.od_pairs
• aperta.routing
• aperta.routing_prep
• aperta.overhead

Accessibility metrics

• aperta.accessibility
• aperta.utility

Traffic flows + calibration

• aperta.traffic_flows
• aperta.calibration

Geographic + network helpers

• aperta.geo_processing
• aperta.geo_mapping
• aperta.network_processing
• aperta.network_snap
• aperta.data_processing

Misc

• aperta.visualization
• aperta.errors