sDNA Software

sDNA Software allows you

  1. to measure your spatial networks in 2D and 3D
  2. to run quick yet effective transport models for cars, pedestrians, cyclists and public transport users

Currently, we support the following software: ArcGIS 10.1+, QGIS 2.13+, Rhino/Grasshopper.  Additionally sDNA can be scripted from the command line, and developers can take advantage of our Python API for any purpose – including experiments in parametric design.

  • Industry standard data compatibility.  Use off-the-shelf Ordnance Survey data and a variety of other spatial formats with a minimum of preparation.
  • Universal network analysis standard.  sDNA uses the network link (the fundamental “atom” from which all networks are constructed) as the base unit of analysis, ensuring compatibility with common data standards. Alternatively, links may be subdivided into polylines.
  • Complex foundations, quick and simple to use.  Use angular analysis as a proxy for human perception of route cost.  (Metric and custom analyses available too).
  • Continuous space and geometry.  Treat network links as continuous, rather than discrete entities to ensure accuracy.
  • Multi-scale.  Customize the locality of analysis, measure accessibility on a range of different scales, or flows for a range of different trip lengths.
  • Customizable.  Use custom link weighting and costing, or zonal weighting if you want – although our research shows this is often not necessary.
  • Accuracy.  The calculation engine is one of sDNA’s greatest strengths, tested against datasets from the literature it achieves equal or better results in all cases.  Every build is also regression tested against a suite of hand-computed networks.
  • Speed.  sDNA supports multi-core CPUs.

 

Measures computed

  • Accessibility within radius (2D and 3D)
    • Closeness (compatible with existing literature)
    • Improved accessibility measures
    • Network gravity model
  • Flows/Betweenness for radius (2D and 3D, single and bi-directional)
  • Network density within radius (2D and 3D)
    • Link count
    • Junction count
    • Total connectivity
    • Total length
    • Total angular cost
    • Total weight
  • Severance (2D and 3D)
    • Total/mean geodesic length
    • Total crow flight distance
    • Mean geodesic diversion ratio
  • Efficiency (2D only)
    • Convex hull area
    • Convex hull perimeter
    • Convex hull maximum radius
    • Bearing of maximum radius
    • Hull shape index
  • Two phase (generation/assignment) model (2D and 3D)
    • Two phase betweenness
    • Two phase destination weight
  • Geometric outputs
    • Geodesics
    • Destination maps
    • Network Radii
    • Convex Hulls
    • Flow Bundles
  • Skim Matrix output

Requirements

  • Please note we are unable to test against all OS and Host Application updates. The standard version of sDNA is free so the best way to check compatibility is to download and try for yourself.
  • OS: Microsoft Windows XP, 7, 8 or 10
  • Host application: one of
    • QGIS 2.8 onwards, or
    • ArcGIS 10.x (Network Analyst extension is NOT required – this saves you a couple of grand), or
    • ArcGIS Pro, or
    • Rhino/Grasshopper
  • Suggested minimum hardware:
    • 1 Gigabyte of RAM, more preferred for large networks.
    • Any modern CPU can run sDNA, but if you want to analyze large networks, the faster the better!
Any questions, please get in touch.