Public open space spatial analysis. Extending and integrating UCL Depthmap on a python-based workflow

João Ventura Lopes (ISTAR-IUL, ISCTE-IUL)

Depthmap (Turner, Varoudis, UCL) is still the standard tool in space syntax analysis. Originally developed for syntactic visibility graph analysis, it also allows the analysis of convex, axial/segment maps, and, generally, of any graph that can have a 2D geometric expression.
This workshop pretends to demonstrate how to explore Depthmap advanced features, how it can be tailored, extended and integrated in a spatial analysis workflow that ties together spatial analysis, data science, geographic information and algorithmic design.

We pretended to show how to:

• Use SalaScript (Depthmap scripting language) to access the graph embedded in each Depthmap file and produce various types of nonstandard space syntax map representations and analysis (e.g. visual graph point, line or area isovists, sliding window and raster like analysis, minimal paths or catchment areas (voronoi diagrams) over visual/axial/segment maps);
• Use the Depthmap Command line interface (cli) in order to automate syntactic analysis;
• Explore new features added to recent versions of Depthmap (e.g. exporting connectivity);
• Combine Depthmap into different digital workflows using Anaconda/python, Rhino/Grasshopper or QGIS/esstoolkit (e.g. importing connectivity into Depthmap or silently run Depthmap).

The workshop will concentrate on public open spaces, using as case studies a set of Portuguese squares’ urban settings. Nonetheless, the introduced concepts and techniques can be easily generalised to architectonic space, and participants may bring their own case studies if they wish.

No previous experience on spatial or syntactic analysis and the mentioned tools are necessary, but the workshop will run smoothly if participants are familiar to some space syntax, Depthmap software, basic python, Grasshopper or GIS from the user's perspective (not mandatory).

We propose a full day workshop (3,5 + 4,0 hours) where participants will explorer the presented concepts, tools and digital workflows mainly in a hands-on approach. The accent will be in the learning by doing, the collaboration between participants, the interactivity with the presenter and the blurring of lines between theoretical exposition and practical exercise.

Proposed Program (3,0 + 4,0 hours, full day workshop):

• Presentation: Welcome and workshop introduction (20 min);
• Presentation: DepthmapX overview and new features (20 min);
• Presentation: SalaScript overview (20 min);
• Hands-on exercises (120 min);
  LUNCH (60 min)
• Presentation: DepthmapXcli (15 min);
• Presentation: Anaconda python and Jupyter Notebooks (15 min);
• Presentation: A python-based workflow (DepthmapXcli – Anaconda/python - Rhino/Grasshopper - QGIS/esstoolkit) (30 min);
• Hands-on exercises (120 min);
• Participants’ presentations and/or discussion of results and possible applicability to their own work/investigations (60 min).

• Participants will get a wide-ranging overview on spatial analysis theories, methods and tools, both from the perspectives of space syntax, geographic systems, urban design and data science;
• Participants will be introduced, or deepen their knowledge, in space syntax Depthmap software and Depthmap scripting language (SalaScript). In the end they should be able to read and interpreter the provided scripts and produce their own;
• Participants will assemble and play with a workflow that gathers tools from different fields: space syntax (Depthmap/SalaScript/DepthmapXcli), data science (Anaconda/python), GIS (QGIS/esstoolkit), and algorithm design (Rhino/Grasshopper). In the end they should comprehend the logic of these python-based workflows and the potential and shortcomings of such computational data-driven approaches to spatial analysis;
• Participants will have the opportunity to discuss, not only the workshop results and expectations, but also their personal work/investigation and the way they foresee the usefulness of these tools and workflows, gathering advices from all participants.

The tuter will bring to the workshop:

• His own laptop, enthusiasm, his knowledge on the subjects and goodwill.
  
  The participants are expected to:
• Bring their own laptops (we will use OS Windows environment, but users of different OSs should have no difficulty to follow);
• Depending on your system (Win, Mac, …), install the correct version and check the running of the following software prior to workshop:
• Mandatory:
• latest version of Depthmap (your OS DepthmapX v0.7.0), (https://github.com/SpaceGroupUCL/depthmapX/releases);
• DepthmapXcli_....exe (your OS DepthmapX command line interface), (https://github.com/SpaceGroupUCL/depthmapX/releases);
• A simple text editor. We recommend a source code editor, like free Notepad++ (MS Windows, https://notepad-plus-plus.org/downloads/) or Sublime (https://www.sublimetext.com/):
• Open-source Anaconda python distribution (latest python 3.x), (https://www.anaconda.com/distribution/);
• Optional (but highly recommended…). For those who would like to follow and get a deeper hands-on into other features and workflows, should install (some or all, in order of importance):
• Rhinoceros3D with Grasshopper plugin (you may run Evaluation for 90 days), (https://www.rhino3d.com/download);
• Extra Grasshopper plugin components (look for latest at https://www.food4rhino.com/):
• Spiderweb, https://www.food4rhino.com/app/spiderweb
• Human, https://www.food4rhino.com/app/human
• GhPython; https://www.food4rhino.com/app/ghpython;
• QGIS (please install version 2.18.1 (LTR: long term release), not the latest):
• Windows OS, https://qgis.org/downloads/
• Mac OS, https://qgis.org/downloads/macOS/
• From within running QGIS install plugin “Space Syntax Toolkit” (esstoolkit) (from top menu bar Plugins/Manage and install plugins)
• Curiosity, enthusiasm and the will to share. Personal experiences, case studies, knowledge and doubts are all welcome.