Fractals

Vlasios Voudouris of the Object-Field Model blog linked to the following talk by Benoit Mandelbrot about "Fractals and the art of roughness." Like Vlasios I found it interesting so I thought I would share it, like him.

On a side note, anyone interested in fractals and want to see them in the context of cities should check out “Fractal Cities: A Geometry of Form and Function” by Professors Mike Batty and Paul Longley. It is a well written, a must read and often cited book for anyone interested in or writing about fractals, urban modeling and complexity sciences. The nice thing about the book is it is freely available at: http://www.fractalcities.org/

agent-based-models.com

Professor Jeff Schank of the Department of Psychology at the University of California is compiling a great website and a resource for those interested in ABM: agent-based-models.com. The site has a plethora of resources for agent-based modelers, including a blog, a list of ABM blogs, simulation environments, Organizations, Centers, and Institutes involved with ABM, a growing list of researchers involved with ABM.

Modeling Housing Markets: Update

A while ago I blogged about the a simple NetLogo model by Nigel Gilbert et al. which explores how some of the main features of the English housing market emerges from the interactions between buyers, realtors and sellers (click here to run the model). I have just come across an audio recording with accompanying slide presentation by Nigel Gilbert’s which enhances the previous post and thought it was worth sharing. Click here to listen and see the slides. The talk is hosted on the SIMIAN (Simulation Innovation: a Node) project website which aims to promote and develop social simulation methods in the UK.

Reference:

Gilbert, N, Hawksworth, J C, and Sweeney, P (2008) 'An Agent-based Model of the UK Housing Market'. University of Surrey http://cress.soc.surrey.ac.uk/housingmarket/ukhm.html or click here to read the paper.

New Working Paper: From Buildings to Cities

Duncan Smith and myself have just finished a new working paper entitled "From Buildings to Cities: Techniques for the Multi-Scale Analysis of Urban Form and Function."

Below is the the abstract for this paper:

The built environment is a significant factor in many urban processes, yet direct measures of built form are seldom used in geographical studies. Representation and analysis of urban form and function could provide new insights and improve the evidence base for research. So far progress has been slow due to limited data availability, computational demands, and a lack of methods to integrate built environment data with aggregate geographical analysis. Spatial data and computational improvements are overcoming some of these problems, but there remains a need for techniques to process and aggregate urban form data. Here we develop a Built Environment Model of urban function and dwelling type classifications for Greater London, based on detailed topographic and address-based data (sourced from Ordnance Survey MasterMap). The multi-scale approach allows the Built Environment Model to be viewed at fine-scales for local planning contexts, and at city-wide scales for aggregate geographical analysis, allowing an improved understanding of urban processes. This flexibility is illustrated in the two examples, that of urban function and residential type analysis, where both local-scale urban clustering and city-wide trends in density and agglomeration are shown. While we demonstrate the multi-scale Built Environment Model to be a viable approach, a number of accuracy issues are identified, including the limitations of 2D data, inaccuracies in commercial function data and problems with temporal attribution. These limitations currently restrict the more advanced applications of the Built Environment Model.

The full title of the paper and reference is:

Smith, D. A. and Crooks, A. T. (2010), From Buildings to Cities: Enabling the Multi-Scale Analysis of Urban Form and Function through the integration of Geographical and Geometric Methods. Centre for Advanced Spatial Analysis (University College London): Working Paper 155, London, England. (pdf)

NetLogo GIS Examples from backspaces.net

While searching for some NetLogo GIS examples I came across this excellent web page by Owen Densmore from Backspaces.net called "NetLogo Bag of Tricks" showcasing NetLogo's GIS functionality. There is a model of water traffic in Venice model and a simple model that reads census data and extracts features,showing them in different colors (both of which can be downloaded).

If any readers know of any other good NetLogo models using GIS data please leave a comment pointing us in the direction of them.