Weighted Mean Direction Surfaces in Python

I work a lot with flows and spatial interactions, one thing that I’ve wanted to do for a while is compute a mean flow direction surface. Unfortunately, arithmetic means don’t work for angular data, this is because it cannot account for the circular nature of the distribution of angular measurements. For instance the angles 5 […]

Continue reading »

Network Population Density for Southwark

Using the excellent SANET extension for ArcGIS 9.3 I was able to take some of my data for Southwark that I had geocoded to address level, and estimate the population density using the OS Mastermap ITN product. The procedure is essentially a Kernel Density Estimation that takes place on a given network rather than across 2D space, this effectively controls […]

Continue reading »

‘Compactness’ in Zoning: the circle as the ideal.

I saw a thought provoking presentation recently, given by Wenwen Li of the University of California Santa Barbara, the talk was a wide ranging insight into Cyber Infrastructure, its uses for geospatial information, and some of the computational techniques that underpinned the project. One element of the project involved zone design for the greater Los […]

Continue reading »

Mapping Spatial Entropy in Southwark

I’ve been doing a bit of work recently on segregation with Pablo Mateos, and having gone through the motions with aspatial indices of segregation (the classics): dissimilarity, exposure and so on, I decided to investigate the more explicitly spatial ones. Taking a lead from Reardon and O’Sullivan’s (2004) paper “Measures of Spatial Segregation” in sociological methodology, I […]

Continue reading »

Finnish Municipalities: A case for zone design?

In Finland, municipalities are incredibly powerful; like local authorities in the UK, municipalities are responsible for local administration, but they also levy an income tax and are responsible for providing most public services. Municipalities were founded on the assumption of equality, which forms the basis for the reform considerations currently ongoing in the Finnish government. […]

Continue reading »