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Hacking on mobile apps with the London crowd

Skrivet av zool den 16 augusti 2015 på English.

I made a last-minute dash down to the London OSM Hack Weekend and had a lovely time there.

I worked on a mobile app which I was pleased to get into a basically working state. It is called osmbi3, which stands for OpenStreetMap Building Information and/or Zombies. The aim was to geolocate the user and find nearby buildings using an Overpass query. This could then be linked to building management information or form the basis for some location-based game. Having managed the basic task, showing a map with annotated every building with an icon reading “yes!”, I set out to try and get OAuth working against the OpenStreetmap server from a mobile device, a task which I have yet to achieve.

So, what last weekend was a very simple but perfectly functional app, is now buggy as hell while it tries to do more. However the source code is on github and i will probably keep working on it, because I could use a very lightweight building editor which doesn’t require any typing.

I am doing a dangerous amount of app development now, helping finish up a project from the last codethecity event in Edinburgh, and working on a dinosaur card game app for - eventually with? - my boy. But it’s all apache cordova and webviews, so i’m not doing anything too evil.

Apart from a successful weekend’s hack, I was very glad to visit London put faces and voices to some names I only know from the internet; also to reconnect with some folks I hadn’t seen for the last ten years. If only more people in the wider community would make the journey up to State of the Map Scotland!

Why i find vector tiles objectionable

Skrivet av zool den 27 februari 2015 på English.

In reply to Steven Feldman on Twitter why do i object to vector tile services, it will definitely take more than 140 characters to explain, and then only partially explain.

The statement that i find vector tiles objectionable was triggered by a positive reaction nonetheless to Mapzen’s Vector Tile Service. I’m fascinated to see it serving up GeoJSON according to a tile-based URL scheme like that in use for raster, imagery tiles.

VectorMap District is an underrated Ordnance Survey Open Data project for mid-scale views of maps. You can get it from the OS open data download pages, selecting from a series of National Grid tiles from what may be a horribly familiar image:

OS national grid

The National Grid tiles that we download with clenched teeth today come from grids and scales designed to be read on paper maps.

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Edinburgh’s map is looking very full. I started doing building editing when I moved here, but now there’s not much to add, so I’ve started to add some building:levels tags in areas I walk through regularly.

An academic project, Mapping Edinburgh’s Social History has been doing a lot of work enhancing Edinburgh map, in particular adding addresses that will allow geocoding without postcodes, which only take you back as far as 1971. One of the MESH mappers, eric_, must be hawkishly watching the map, saw a recent batch of my edits and suggested that I start adding in roof:levels and building:material “but no pressure!”

While i’m into doing this if it has value to others and i’m surveying anyway, I have my doubts about building interpretation in a city full of architectural idiosyncracies such as Edinburgh. One is, what happens when the top storey of a building is embedded within a roof, like this?

mix of building:levels

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Missing Maps Mapathon Edinburgh, episode 2

Skrivet av zool den 19 februari 2015 på English.

The local Missing Maps organisers are keeping up the pace with the mapathons happening in Edinburgh every couple of weeks at the moment.

This time the word got out to the OSM community with plenty of notice, and the mapathon was duly mobbed by the Usual Suspects. I enjoy the pub meets as much as some, so it was a good chance to catch up with chrisfl, drnoble, fozy81 and eisa, while stevefaeembra was busily OCD mapping up a storm again, and we even flushed out Bob Kerr from his OSM semi-retirement, full of curiosity and helpfulness as ever.

This was my first attempt to ever use the HOT tasking manager in anger and I remain unconvinced about the validity of the task. The interpretation of aerial imagery remains delicate and uncertain, and the currency of date in the imagery is unknowable. How useful this is to displaced communities seeking shelter, who can tell? Are tracks to farm buildings really missing on the map? Is tagging for the renderer appropriate at the level of detail where a road may be a service road, residential, or a track, according to the iD pre-sets?

Meanwhile, many of the tasks marked as open seem almost complete; as a casual mapper, not familiar with the HOT standards of quality, i would have a hard time marking most squares as “Done” and it appears others have similar existential problems. One wants to create useful work, not busywork, for those validating the maps on the ground. As I’m mildly stricken with a cold and indulging in a “duvet day” today, I may keep going with some of the random tasks on the grid.

I’m partially converted to the iD editor, though the usual gripes came up in the general discussion - it remains far too easy for a new user to start deleting objects without an explicit check or warning or an obvious means of rowing back. We hear that RichardF has a relevant patch in, and deserves cake, let’s hope it gets accepted and released soon.

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Who are the Missing Mappers? Part II

Skrivet av zool den 5 februari 2015 på English.

While the inaugural Missing Maps mapathon in Edinburgh was a positive event, there are a few changes I’d make that I hope would improve the outcomes.

First, I’d make more effort to lead new mappers into the local community. I would emphasise that contributing to OpenStreetMap is not primarily about “armchair mapping”, but about local surveying, adding to and maintaining the map of one’s local area. There are regular meetups and mapping parties in many areas, and where there are not yet, a missing maps event presents a great chance to bootstrap a more active surveyor community.

I appreciate that in areas where the Humanitarian OpenStreetMap Team and The Missing Maps are focusing, there may not be local mappers with the leisure, infrastructure and bandwidth to contribute surveyed data to OSM, but it is almost always more work to correct poor armchair mapping than to build up from the ground.

Notes in progress:

NLS historical imagery, JOSM benefits of multi layers, iD and tag prescription, this was a technical audience and yes it was well balanced also

Who are the Missing Mappers?

Skrivet av zool den 5 februari 2015 på English.

I had the fun experience last night of dropping in to an event organised by The Missing Maps. Unfortunately I couldn’t make the whole thing, nor could most of the local mapper community members in Edinburgh, as we only found out that the event was happening the evening before :/

This seemed to be an accident of occupying parallel, not quite overlapping, social media universes. The main channel for OpenStreetMap Scotland news and events tends to be the OSM Alba Twitter feed and we organise mapping parties via the wiki, with the Scotland mailing list a fairly new addition to the communications tools.

Whereas The Missing Maps are organising via Facebook and eventbrite mostly. I don’t know about you, but i tend to treat eventbrite as read-only, and I’ve historically refused to actively participate in Facebook. So we failed to overlap, and this wasn’t helped by the University of Edinburgh-hosted venue moving at the last minute. So garycmartin attempted to drop by but went to the wrong venue and couldn’t find a redirect. But the indefatigable stevefaeembra went along and represented well for the local mapper community.

I could only make the central 45 minutes, and got stuck on one question about recommended tags for roads, to which my answer was suffixed with “and this is my personal opinion, and there are many personal opinions in the OSM community”.

I have a few thoughts to share about the experience of seeing newbie mappers get a copious and well-thought-out introduction to the iD editor, but i’ll save those up for another diary entry. Despite the teething trouble with the venue and the community links, it was a worthwhile event, very well attended by a diverse looking group of people, many of whom turned out to be students on the University of Edinburgh’s MSc GIS course, and i saw an old colleague from the EDINA datacentre there; always glad to see OSM bringing people together in unexpected ways.

Plats: Southside, City of Edinburgh, Scotland, United Kingdom