Spatial network analysis software

Spatial network analysis software packages are computer tools used to prepare various graph-based analysis of spatial networks. They stem from various research fields in transportation, architecture and urban planning. The earliest examples of spatial network analysis using computers include the work of Garrison (1962), Kansky (1963), Levin (1964), Harary (1969), Rittel (1967), Tabor (1970) and others in the 1960s and 70s. Various fields of study have later developed specific spatial analysis software to suit their needs, including TransCAD among transportation researchers, GIS among planners and geographers, Axman among Space Syntax researchers, and various plugins for other software platforms. The list below gives and overview of some of the available software. Many of these were developed in academia and are freely available or freely available for academic research.

In historical order:

• Axman The (near) original developed by Nick Sheep Dalton of UCL to perform axial line analysis on computers running Mac OS, currently used in more than 50 countries. This spawned many offshoots such as Pesh (for the analysis of convex space networks) and SpaceBox (for the analysis of 'all-line' axial maps).
• Spatialist Developed at Georgia Institute of Technology to implement theoretical innovations principally introduced by John Peponis, this software is plugs into the MicroStation CAD package to analyse networks of automatically generated 'e-spaces' and 's-spaces'.
• Axwoman 1.0, written by Bin Jiang while at UCL, is a tool to perform axial analysis as a plug-in to ESRI products.
• Axwoman 6.2, evolved from Axwoman 1.0 and many years of research by Bin Jiang and his team. Axwoman 6.2 is a free plug-in to ArcMap 10, combined with AxialGen in one single installer. Featured functionality include automatically generating natural streets and axial lines from OpenStreetMap data. The website also contains a set of tutorials for self-learning.
• Depthmap Developed by Alasdair Turner of UCL, this software was first developed to generate isovists and perform visibility graph analysis of building systems on computers running Windows, but now includes the automatic generation of axial line networks and analysis of axial line networks and road segment line networks at anything up to the level of the USA or Europe.
• OmniVista Developed by Nick Sheep Dalton and Ruth Conroy Dalton to perform a range of isovist measures on Mac OS computers.
• Fathom, a commercial implementation of visibility graph analysis written by the Intelligent Space Partnership.
• Mindwalk Developed by Lucas Figueiredo, This software performs spatial analysis over standard axial maps and new continuity maps. It is written in Java and runs on several platforms. Also known as xSpace, Mindwalk has been used as a research and teaching tool at several institutions since 2002 and now it is being distributed worldwide for academic and non-commercial purposes.
• Isovist Analyst by Sanjay Rana while at UCL, this program creates isovists from building plans as a plug-in to ESRI products.
• Ajanachara. Open source software developed by Gerald Franz at the Max Planck Institute for Biological Cybernetics to perform visibility graph analysis of 3D Studio Max and VRML models.
• Webmap Also developed by Nick Sheep Dalton at UCL, this software is free to use (although it requires registration), and allows users to analyse axial maps through a web browser interface.
• Confeego Developed by the commercial company Space Syntax Limited, but available free for academic use, this software plugs directly into MapInfo Professional to analyse line axial networks.
• AJAX by Mike Batty of UCL, performs both traditional axial network analysis (Batty calls this the primal analysis), and point-based visibility analysis introduced by Bin Jiang (which Batty calls the dual analysis). In a recent paper, Batty shows the elegant mathematical relationship between the two analyses.
• OverView plug-in to AutoCad by Christian Derix for Aedas Architects in collaboration with the Center for Evolutionary Computing in Architecture CECA. Allows architects to do quick visual integration mapping via isovist analysis on their projects. Contains also the possibility to analyse non-planar environments to take volumes and hilly sites into account.
• AXess 1.0 by Jennifer Brisbane at the City University of New York. A context menu tool for ArcGIS 9.x that calculates connectivity, control, mean depth, global integration, and local integration for all nodes in an axial line layer. Free download available at ESRI ArcScripts.
• Webmap-At-Home by Nick Sheep Dalton OU. A Java implementation of the original Axman program with a number of extra features added. This is a platform neutral full application capable of reading DXF files and the original Axman binary format. Free download available at .
• AxialGen by Bin Jiang and Xintao Liu at the University of Gävle, Sweden. It is a plugin to ArcGIS 9.2 that generates automatically the axial lines for a complex polygon with holes.
• Layout-iQ Developed by Nelson Lee at Rapid Modeling. Used extensively in healthcare, manufacturing, banking, retail, and office space, Layout-iQ is a software that evaluates the frequency of flow in a workspace and measures the total travel distance that resources will travel to navigate through the workspace. The software integrates CAD drawings with a diagram of flow between points. The thickness and color of the flow lines indicate the intensity of flow in each line, so users can visually see high priority point to point relationships. As the user moves locations in the diagram, the software dynamically calculates the impact on travel distance and users can immediately see the impact of the change on operations. The software also allows for the creation of improved aisles and paths using the aisle effectiveness measurement and actual path diagramming.
• Urban Network Analysis Toolbox for ArcGIS (free, open-source) Developed by the City Form Lab at SUTD and MIT. The UNA Toolbox can be used to compute five types of graph centrality measures on spatial networks: Reach; Gravity; Betweenness; Closeness; and Straightness. The tools incorporate three important features that make them particularly suited for spatial analysis on urban street networks. First, they can account for both geometry and topology in the input networks, using either metric distance (e.g. Meters) or topological distance (e.g. Turns) as impedance factors in the analysis. Second, unlike previous software tools that operate with two network elements (nodes and edges), the UNA tools include a third network element – buildings – which are used as the spatial units of analysis for all measures. Two neighboring buildings on the same street segments can therefore obtain different accessibility results. And third, the UNA tools optionally allow buildings to be weighted according to their particular characteristics – more voluminous, more populated, or otherwise more important buildings can be specified to have a proportionately stronger effect on the analysis outcomes, yielding more accurate and reliable results to any of the specified measures. The toolbox is built for easy scaling – it is equally suited for small-scale, detailed network analysis of dense urban areas as it is for sparser large-scale regional networks. The toolbox requires ArcGIS 10 software with an ArcGIS Network Analyst Extension.
• Urban Network Analysis Plugin for Rhinoceros3D (free for both academic and commercial use) Developed by the City Form Lab at SUTD and MIT. The Rhino UNA Toolbox can be used to compute five types of graph centrality measures on spatial networks: Reach; Gravity; Betweenness; Closeness; and Straightness. The toolbox also include a series of other spatial analysis tools, such as Closest Facility, Alternative Routes finding, pedestrian flow modeling along shortest or redundant paths, facility patronage estimation, spatial distribution of origins weights along routes etc. The tool gives users full control to specify which origins and destinations to use in the analysis and allows the users to weight the analysis with specific attributes of each origin and destination. The UNA Rhino toolbox was developed in order to make spatial network analysis tools available to architects, designers and planners who do not have access to GIS and typically work on designs in Rhino. Having UNA metrics in Rhino, not only allows one to analyze how a specific spatial network performs, but to also incorporate the analysis into a fast and iterative design process, where networks can be designed, evaluated and redesigned in seamless cycles to rapidly improve the outcome.The UNA Rhino toolbox is significantly faster that its GIS counterpart, which has been available as a plugin for ArcGIS since 2012. Users also have an ability to rapidly create and edit networks from any Rhino curve objects, making network design and redesign simple and intuitive. The analytic options available to the user have expanded, giving you more precise control to analyze exactly what you need for every unique spatial network problem.The toolbox requires Rhinoceros version 5 software with the latest updates (SR 10 or later). Help documentation for the UNA Rhino plugin is also available from the City Form Lab website.
• SSA Plugin by Burak Beyhan at the Mersin University, Turkey. Space Syntax Analysis (SSA) Plugin is operational on a series of Free and Open Source Software for GIS (FOSS4GIS) including OpenJUMP, gvSIG, OrbisGIS, QGIS, OpenEV, Thuban, MapWindow GIS, SAGA, and also R Project. SSA Plugin calculates the standard space syntax measures including connectivity, total depth, mean depth, global integration, local depth, local integration and control values for each feature involved in a spatial configuration, and intelligibility value for the whole of the configuration. In addition to these parameters, users are also allowed to export adjusted graph created by the plugin to an external file in a Social Network Analysis (SNA) file format for further analysis of the spatial configuration concerned in the respective software environment.
• depthmapX Developed by the depthmapX development team, is open source multi-platform spatial network analyses software based on the original Depthmap. It can generate isovists and perform visibility graph analysis of building systems on computers running Mac OS X, Windows and Linux, it includes automatic generation of axial line networks and analysis of axial line networks and road segment line networks. depthmapX is based on Qt framework.
• Spatial Design Network Analysis (sDNA 3D) Since 2011, developed by Alain Chiaradia, Crispin Cooper and Chris Webster at Cardiff University and University of Hong Kong, (free) a tool aiming to unify the use of spatial network analysis in the disparate fields of design and research. To this end, plugins are provided for Autocad (for designers), ArcGIS, open source QGIS (for analysts & designers) and a standalone Python version that works on 2D or 3D shapefiles enabling use in other GIS software and custom projects. sDNA standardizes on the network link as a unit of analysis, and computes a wide variety of closeness, betweenness, severance and efficiency measures. sDNA works with 3D topography and 3D multilevel environment. Analyses and Radius can use Euclidean, angular, topological or custom distance metrics, and link, length or custom weightings. In Angular analysis mode sDNA computes cumulative angular change along the link and angular change at junction resulting in angular geodesic.
• ORA Developed by Dr. Kathleen M. Carley and the joint Carnegie Mellon University and Netanomics team is a tools that support social and spatial network analysis. It is interoperable with other spatial analysis tools such as ARCGIS. See also Dynamic Network Analysis.