City2Graph · Map an OD matrix

Turn an external origin-destination flow matrix plus a zones layer into a spatial graph, with edges between zone centroids weighted by flow. Mirrors the Mobility panel.

Needs a zones object (polygons) with a unique ID column, loaded with Load File in Import urban data, and an OD matrix CSV of flows between those same zone IDs.

1. Set the zones

Set the Zones Object and the Zone ID Column (zone_id, for instance). The IDs there have to match the ones in the matrix.

Selecting the zones object and ID column.

2. Load the OD matrix

Set the OD Matrix Path and the Matrix Type. Adjacency needs nothing further; Edgelist also needs the Source, Target and Weight columns.

Loading the OD matrix and mapping its columns.

3. Build the OD graph

Threshold drops weak flows and Directed decides whether the result keeps direction. Edges are drawn between zone centroids and weighted by flow.

The OD flow graph between zone centroids.

Next steps

Post-process a graph: filter, clip or build isochrones.