Category Archive: GIS

Network analysis video – 7th Scottish QGIS user group

Network analysis presentation from the 7th Scottish QGIS user group. Featuring Ordnance Survey open data, QGIS, GRASS and R.

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Spatial networks – case study St James centre, Edinburgh (2/3)

This is part two in a series I’m writing on network analysis. The first part is here. In this section I’m going to cover allocating resources, again using the St James’ development in Edinburgh as an example. Most excitingly (for me) the end of this post covers the impact of changes in resource allocation.

Spatial networks – case study St James centre, Edinburgh (1/3)

Last year I spent a bit of time learning about routing and network analysis. I created a map of distance from each GB postcode to the nearest railway station. At the time my… Continue reading

R with GRASS GIS – easiest Munros

I’ve been having a more sustained play with R and GRASS together. I’ve previously used them, in tandem, for processing satellite images, but haven’t been much further. In this post I’ll look at… Continue reading

R – iteratively changing column classes

When you write an ESRI Shapefile from R, writeOGR assumes your numeric fields are real numbers and so you get a lot of redundant zeros appended. This is misleading and distracting when you… Continue reading

R – Change columns names in a spatial dataframe

Ordnance Survey have a great OpenRoads dataset, but unfortunately it contains a column called ‘primary’, which is a keyword in SQL. This makes it challenging/impossible to import the OpenRoads dataset into a SQL… Continue reading

Converting (British) National Grid references

I was supplied spatial point data this summer where the locations were detailed in Ordnance Survey’s National Grid (NGR) format. If you’re not familiar with it, rather than using eastings and northings (in… Continue reading

EARL 2016 talk

I spoke on 14th September at the EARL (Effective Applications of the R Language) conference in London. This is event is concerned exclusively with the R programming language and it was the first… Continue reading

Mapping from GPS files

I’m just back from a 7 day cycle tour of Arran, Islay, Bute and the bits in between. I wanted to create a map of the route from the GPS log files of… Continue reading

Monthly patterns in Scottish snow (1946-2006)

There’s been a bit of a flurry on Twitter recently about April snow in the UK (see tweet below). My opinion is there’s often UK snow during April, but it happens to be… Continue reading