QNEAT - QGIS Network Analysis Toolbox

About QNEAT

QNEAT (formerly known as QNEAT3, see the legacy/archive page) is a QGIS plugin that is written in Python and is integrated in the QGIS3 Processing Framework. It offers advanced network analysis algorithms that range from simple shortest path solving to more complex tasks like Isochrone Area (aka service areas, accessibility polygons) and OD-Matrix (Origin-Destination-Matrix) computation. Upgrading from QNEAT3? See Changes from QNEAT3.

All algorithms make use of the QGIS3 Python API, especially the graph analysis classes that are written in C++. This lays a positive basis in terms of algorithm performance as the heavy computing (like dijkstra algorithm) is performed using C++ machine code. Iso-Area generation is built on GDAL for raster I/O and contouring — as of version 4.0, QNEAT no longer requires the matplotlib library.

Porting a project or Processing model from QNEAT3? It won't run unmodified — watch for:

Algorithm IDs changed; saved models must be re-linked to the new algorithms.
8 Iso-Area algorithms consolidated into 6 — the Polygon/Contour variants now share one algorithm with an extra type parameter.
OD-Matrix from Points as CSV (n:n) was removed; use the Table variant and save as .csv instead.
Parameter names changed across the board (e.g. Start/End & From/To-Point → Origin/Destination point).
The “Entry Cost calculation method” parameter has been removed — entry/exit cost is now always ellipsoidal.

For the full details have a look at Changes from QNEAT3.

Author

Clemens Raffler
Mobility Researcher, GIS-Enthusiast
Vienna, Austria

Twitter | Github: @root676
LinkedIn: Clemens Raffler

Github Repository: QNEAT3

Map showing a shortest path route computed by QNEAT

Data Source: Stadt Wien – data.wien.gv.at

Shortest Path Algorithms

Pathfinding algorithms are the name and the game of network and graph analysis. Using the QGIS3 implementation of the Dijkstra Algorithm, this algorithm computes the geometry and costs along the shortest path between two points.

Map showing isochrone service areas computed by QNEAT

Data Source: Stadt Wien – data.wien.gv.at

Iso-Area Algorithms

Iso-Areas are essentially the network-based version of buffers. They answer questions like 'How far can i go on a network when travelling 2500 meters from a given Startpoint on a street network?'. Several approaches to compute Iso-Areas are implemented.

Origin-destination matrix visualization computed by QNEAT

Data Source: Stadt Wien – data.wien.gv.at

OD-Matrix Algorithms

OD-Matrix algorithms - in case of the QNEAT plugin - compute the travel cost on network (either routed distance or routed time) between all combination of points in a layer. Travel cost on network without computing the shortest path geometry? These algorithms do the job!