The latest outputs from researchers, alumni and friends at the UCL Centre for Advanced Spatial Analysis (CASA).
I’ve been playing with the much-enhanced raster support in PostGIS 2.1 in the last few days. Amongst other things I’ve been producing maps with ST_MapAlgebra, which has changed a little since 2.0. The example callback function in the documentation is somewhat unhelpfully bare-bones: it always returns 0, touching none of its arguments. So here’s an […]
Continue reading »I’ve been playing with the much-enhanced raster support in PostGIS 2.1 in the last few days. Amongst other things I’ve been producing maps with ST_MapAlgebra, which has changed a little since 2.0. The example callback function in the documentation is somewhat unhelpfully bare-bones: it always returns 0, touching none of its arguments. So here’s an […]
Continue reading »Since light can affect happiness, two important pieces of environmental data I add to the Mappiness data set during analysis are: (1) whether a response was made in daylight; and (2) day length when and where the response was made. To derive these, I need the date, time and location of the response, and sunrise […]
Continue reading »Since light can affect happiness, two important pieces of environmental data I add to the Mappiness data set during analysis are: (1) whether a response was made in daylight; and (2) day length when and where the response was made. To derive these, I need the date, time and location of the response, and sunrise […]
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Imagine you want compare various locations in terms of the availability of a certain type of environment, such as fresh water. You might want to use a measure of the proximity of that environment — such as the nearest neighbour distance. You might want to use a measure of the quantity of that environment in […]
Continue reading »Updated May 2012 for Lion The secret to getting the MySQL gem to install and function with Ruby 1.9.x on Snow Leopard or Lion is: Install MySQL using the 64-bit .DMG package installer from dev.mysql.com Install Ruby using RVM or (preferably) rbenv Add …
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