John Gray on maps and cities.

A map can represent the physical structures of which a city is at any one time composed, but the city itself remains uncharted. This is not only because the city will have changed materially by the time the map appears. A map cannot contain the infinite places that the city contains, which come and go along with the people who pass through them. The map is an abstraction, simplifying experiences that are incomparably more variegated.

From The Silence of Animals. John Gray

Leeds Data Thing, Maps and Hackdays

Leeds Data Thing is a new group started in Leeds  (not to be confused with Leeds Ruby Thing!).

I spoke at the first event (read the write up from Rebecca) about Geospatial visualisations and  OpenStreetMap: Here are the slides:

Since then there has been a few other events as part of Big Data Week - including a load of great short talks.

This weekend there was a data hackday at the UK’s NHS Information Centre for Health and Social Care in the centre of Leeds.

hipster photo

There’s a wealth of data on their website , but it was given to us as a mysql database, and we were able to enter remotely. On the first day I poked around the data and had a thought.


I often spend the first part of any hackday wondering what to do, and twiddling thumbs. I find that hackdays become for me a type of busman’s holiday – and this hackday was particularly geographical in nature. Most of the entries had some kind of data on map component. I think that these types of analyses, whilst being very smart and interesting – and may be exactly what the judges are looking for, may not exactly stretch the unexpected or “the hack” in the data.

Fortunately there was plenty of latitude for exploring things laterally. The most interesting dataset was listing the chemicals and drugs each practice spent money on – but I couldn’t find much to do with it.   What caught my eye was the dataset listing the names of the doctors surgeries, practices, medical centres. If I think about my neighbourhood I can pass about half a dozen doctors in a very small area. Leeds is well covered (or perhaps just my area is!) . I was reminded of James Joyce’s quote about being unable to cross Dublin without passing a pub. Perhaps the same can be said for Leeds and doctors!  The names of the surgeries were also interesting. Names such as:

Chapeloak Surgery
The Avenue Surgery
Dr Ca Hicks’ Practice
The Dekeyser Group Practice
The Highfield Medical Centre
Chapeltown Family Surgery

Wonder if the more “leafy” the name, the more “leafy” the neighbourhood it was in? Perhaps the more grandiose sounding practices had more patients? Perhaps the smaller sounding ones had better patient satisfaction reviews?

At the venue, it appeared that I was the only one to be using Linux on the desktop and so the wifi did not work – so I had a bit over one hour to put something together. Decided to go with the concept of “Leeds is covered” and wanted something showing the labels of the practices over the areas where they were. Filling out the map, so to speak.  The hack was called “Tim’s One Hour Data Challenge” and here is the end result:

Leeds is covered

Leaving GeoIQ/Esri. Retrospective and future plans.

I’ve been with GeoIQ (the folks behind GeoCommons) since the Summer of 2010, and I’ve loved it. Earlier this year GeoIQ joined with Esri and we were hugely excited to change things from the inside and coming up with plans for the new Esri DC Dev team.. However, that’s all behind me now, alas, as it was time to move on. I have left GeoIQ/Esri to be a freelancer and to join the Topomancy coop. This post will take a quick look back at time well spent, and will touch upon what I will be doing in the future.

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Pubs in England – geographical distribution of names with cardinal points.

This image shows 4 maps of pubs in England where the pub names have a cardinal direction in the name. North, South, East and West. You can try searching for any pub name here.  For example, West = “The Great Western”, “The Westbourne”. North  = “Northcote Arms”, “The North Pole”

There appears to be more North pubs in London than anywhere else, and more West pubs in the north (and north west?) of England… running on a faster, newer server! has finished maintenance work – I really should get rid of the beta sign now. Anyhow its running on a much faster site, courtesy of So performance should be better now. All user accounts and maps and points should have been transferred seamlessly. georectify maps georeferencing fun!

I’m still configuring the mail server, so if new users when signing up are seeing mail in spam boxes, let me know!


268 Different Colourful Tiles – Plain Tile Maker

Plain Tile Maker was my weekend project – a mapping tile service that serves one colour tiles as a tile basemap.
There are about 268 colours to choose from – basically anything that the underlying library (Imagemagick) supports.
It was developed for me to play around on the Heroku platform, and as a response to a user question, where the user wanted a way to show just a plain one colour background.
This solution is more flexible, and really easy.






The format is

So for example,

And in return you get a 256×256 sized image of that colour.



You can use it in your mapping libraries, for example: With OpenLayers:

var colourTile = new OpenLayers.Layer.XYZ(
 "Plain Colour Tile",
 { sphericalMercator: true,
 buffer: 1,
 numZoomLevels: 17

And with Leaflet:

new L.TileLayer('{x}/{y}/{z}.png', {maxZoom: 18});

Or you can add them to GeoCommons quite easily. Add{X}/{Y}/{Z}.png

in the Add a URL link, choosing Map Tile URL from the format, and  then give it a nice name when prompted.

Here’s the Bisque tiles in GeoCommons.

I’ve used the in a map it to give a ghosting effect over the basemap, and to just show my own boundaries.  is a map made with some World Boundaries over the plain bisque map we had just added. I’ve also overlaid the Acetate Labels layer on top for context.

Want to know more? The code for this is on github.