Version 0.1.1 of the package stplanr has been released on CRAN. This is a major update with many new functions and a new class definition, SpatialLinesNetwork, for route planning and network analysis using igraph. This short post, by myself and package co-author Richard Ellison describes how stplanr can be used for ... [Read more...]

Open source software has caused a quiet revolution in computing since the creation of the GPL license by Richard Stallman back in 1989. Yet it has been slow to gain ascendency in many areas, including Civil Engineering. This short post discusses this issue in the context of the uptake of QGIS ... [Read more...]

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A useful feature of R is its ability to implement a function differently depending on the ‘class’ of the object acted on. This article explores this behaviour with reference to a playful modification of the ‘generic’ function plot() to allow plotting of cartoon bicycles. Although the example is quite simple ... [Read more...]

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It has been possible for some years to launch a web map from within R. A number of packages for doing this are available, including: RgoogleMaps, an interface to the Google Maps api leafletR, an early package for creating Leaflet maps with R rCharts, which can be used as a ... [Read more...]

I recently delivered a workshop on a practical introduction to shiny, an R package that enables development, testing and deployment of interactive web applications. Delivered at the University of Sydney’s Institute for Transport and Logistics Studies (ITLS), it was designed for people who are a) fairly new to R (... [Read more...]

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These are the slides from a presentation today at the European conference of the IMA, held in Maastricht, 23rd to 24th October, 2014. Microsimulation, as its name suggests, is about modelling things at the individual-level. In practice, this usually means estimating the characteristics of people using statistical or econometric techniques. Microsimulation, ... [Read more...]

I recently attended a week-long R course in Newcastle, taught by Colin Gillespie. It went from “An Introduction to R” to “Advanced Graphics” via a day each on modelling, efficiency and programming. Suffice to say it was an intense 5 days! Overall it was the best R course I’ve been ... [Read more...]

I was recently invited to write a book review for Applied Spatial Analysis and Policy (ASAP). The book, I conclude, “is the authoritative resource on R’s spatial capabilities” and should be of interest to many R users. Below is a preprint of the full review, now published on ASAP’... [Read more...]

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The version control system Git is an amazing piece of software for tracking every change that you make to a project and saving its entire history. It is incredibly useful, for users of R and other programming languages, leading it shoot from 0 market share in 2005 (when it was first released) ... [Read more...]

The 'regex' family of languages and commands is used for manipulating text strings. More specifically, regular expressions are typically used for finding specific patterns of characters and replacing them with others. These technique have a range of applications and R's base installation has powerful regex tools (not to mention add-on ... [Read more...]

With ubiquitous collection devices (e.g. smartphones), having too much data may become an increasingly common problem for spatial analysts, even with increasingly powerful computers. This is ironic, because a few short decades ago, too little data was a primary constraint. This tutorial builds on the 'Attribute joins' section of ... [Read more...]

After a colleague of mine requested an illustration of the aggregation technique that was part of an introduction to spatial data in R, I decided to revisit aggregation. The first article I posted here on the subject used data from London; this one is slightly different, using Twitter data aggregated ... [Read more...]

On 24th January 2014 I ran a one day practical course on an "Introduction to Spatial Data Visualisation in R" at the University of Leeds, with the help of demonstrators Rachel Oldroyd and Alistair Leak, who came up from London for the event. The course is designed for people completely new ... [Read more...]

A common task in GIS is comparing the spatial extent of one layer with another. Say you have a load of points, some of which overlay a polygon layer. You are only interested in the points that intersect with the points. What do you do? Also, how can you aggregated-up ... [Read more...]