Tuesday 26 July 2016

Urban road network data for 80 world cities

A recent study published in Nature's Scientific Data caught my eye recently. In the paper, published online on 21 June 2016, the authors describe a method for taking OpenStreetMap (OSM) data and producing usable, toplogically accurate network data from it. It covers 80 of the biggest cities across the world, from Tokyo to Medellin. What caught my eye in particular is that they shared all the data on Figshare, and you can download it in chunks or the whole lot at once (2.15GB). I had a little play with it and made some night time/from space views of the network data, just for fun. Guess the cities below (helpful clues included)... and then tell me which is the odd one out.

Clue: it's not Bognor Regis 

Clue: I have been there (that's not very helpful, sorry) 

Clue: lots of people live here

Clue: rhymes with Few Dork

Clue: lots and lots and lots of people live here

Back on topic now - here's what the study looks like if you haven't already clicked - the authors also provide loads of useful resources in the paper. They also describe how they were able to develop a topologically accurate street network using their GIS-based protocol.

Take a look at the study - it's great

The 80 cities featured

Citation: Karduni,A., Kermanshah, A., and Derrible, S., 2016, "A protocol to convert spatial polyline data to network formats and applications to world urban road networks", Scientific Data, 3:160046, Available at http://www.nature.com/articles/sdata201646

Friday 15 July 2016

From CartoDB to CARTO - the future of interactive mapping?

I've been using CartoDB (now CARTO) for a few years for interactive mapping - and have always loved what it can do - from basic mapping to much more complex analysis. Now, with the re-brand as CARTO and the advanced analytical tools available through the new Builder interface it's on a new level. So, credit where credit's due - I thought I'd do a short piece on this now to give my take on the new interface. But first, here's a little gif of me playing around with some commute data - which you can also download yourself if you want to. The dataset was used as part of a project I've been working on with Garrett Nelson - but hopefully more on that in future.

I'm just playing around turning things on and off here

If you've used the old CartoDB interface, the new Builder one might be a bit confusing at first - though you may not actually be able to get access to it yet. But once you have played around with it for a few minutes it soon becomes pretty intuitive. I uploaded a sub-set of commute flow lines for Minnesota and Wisconsin and then decided to add widgets so that I could filter the data using line distance, FIPS codes and commute volumes - as you should be able to see in the larger image below.

Click to enlarge - change the data view by using tools on right

This is very much just a little data sample, but if you want to play around with the interactive CARTO map you can see it here. It's not very pretty and the origins and destinations don't have place names right now - only FIPS codes - but the principle is the same. The Widget interface takes a little bit of getting used to as well, but is really easy to use once you've figured out what's what. See below for a screenshot.

You can add widgets for different data types

Any negatives to report? For me, not now. I'm just enjoying the enhanced analytical tools at hand. But if I was being greedy... I'm not massively keen on the default legends, there doesn't appear to be an 'addition' blend mode and the snap alignment of shapes in the old map editor has me a little flummoxed, but these are minor grumbles.

I'm not getting paid to promote this and I don't know anyone at CARTO - honest - I just think they have produced something that works brilliantly, is simple yet powerful and allows us to manipulate, analyse and share our data in new ways. There are other tools out there but the new Builder, for me, takes things to the next level for a mass audience. To answer the question in the title of the blog: is CARTO the future of interactive mapping, then? Not the future, but probably a very big part of it.

Notes: really, they didn't pay me. Data used are from the American Community Survey. I wrote a working paper on it already. I also blogged about it on my old blog. Finally, if you're one of the few people in the world not to have seen it, Mark Evans created this beautiful site with the same data.