[Talk-us] identifying TIGER deserts

Fri Dec 7 23:09:50 GMT 2012

Something else that would be cool for the US OSM server is a tilecache
proxy of publicly available, kosher data sources

On Fri, Dec 7, 2012 at 5:07 PM, Michal Migurski <mike at teczno.com> wrote:

> Thanks!
>
> I agree about a regularly-updated map. For this one, I used the up-to-date
> osm2pgsql database that Ian Dees is maintaining on the OSM-US server we
> have living in Oregon, an awesome resource for USian OSM things. =)
>
> I re-projected everything to spherical albers, and then iterated over
> every grid square in the raster and did a simple Postgres SUM(ST_Length)
> query for the roads in that area. The data was written out as a set of
> Float32 rasters, which I later combined with Numpy to make pretty pictures.
>
> -mike.
>
> On Dec 7, 2012, at 1:09 PM, Alex Barth wrote:
>
> > Mike -
> >
> > AWESOME looking map and similar to what Ian and Ruben are working on.
> Would you be open to share how you built that map? How hard (time
> consuming) is it to regenerate?
> >
> > I'd love to get a regularly updated map out there showing TIGER deserts.
> We'd use that ourselves to start fixing some of the worst areas in terms of
> geographic accuracy. But obviously such a map would be a good thing to have
> for the wider community.
> >
> > On Dec 7, 2012, at 1:32 PM, Michal Migurski <mike at teczno.com> wrote:
> >
> >> That's great!
> >>
> >> I've been thinking about some of the same things, inspired by Dennis
> Zielstra's talk at SOTM-US. I'm looking at road lengths for 1x1 kilometer
> squares, measuring OSM user count (post-import) vs. possibility for
> improvement between 2007 and 2012 TIGER/Line data:
> >>
> >>      http://mike.teczno.com/img/osm-users-imports-2012-09.png
> >>      - Blue means 2012 data would be an improvement
> >>      - Red/Yellow means there are active OSM users there
> >>
> >> I used an Albers equal-area projection to ensure correct length and
> density regardless of latitude, and my intent for this is to produce
> county-by-county views that GIS managers in different jurisdictions can use
> to understand whether their data is worth important, and what OSM users
> they'd need to contact in order to be successful.
> >>
> >> I have a slippy map version of this but the projection registration is
> off by a few hundred meters; need to figure out why that is and fix it.
> >>
> >> -mike.
> >>
> >> On Dec 7, 2012, at 10:00 AM, Ian Villeda wrote:
> >>
> >>>
> >>> Hey team,
> >>>
> >>> Over here at MapBox we were inspired by Martjin's great post on
> identifying TIGER deserts[1], so we're attempting to effectively identify
> TIGER deserts for the rest of the continental U.S. (sorry Hawaii + Alaska,
> you're next). The goal is to create a slippy map from zoom level 2 to 15(?)
> such that it's easy to find the places in need of the most love.
> >>>
> >>> We have a osmium-genereated postigs database with all ways tagged as
> highway=* and their version number. The plan to run the analysis against a
> 5x5 km grid, although we will probably play with the size of the gridcell.
> Another option might be to conduct the analysis and varying levels of
> granularity.
> >>>
> >>> We're still consiering different methods of analysis - the goal being
> to normalize way density to display better identify TIGER deserts. We'd
> would love your thoughts / input / reactions. A few ideas we've tossed
> around / are activley pursuing:
> >>>
> >>> - percent of version 1 and/or 2 ways in each gridcell
> >>> - average number of version 1/2 ways per gridcell
> >>> - using a threshold value(s) similiar to Martjin's approach
> >>> - [your ideas here]
> >>>
> >>> Ultimately we'd like showcase the rendered results in site that would
> make editing TIGER deserts easy. For now though this is just a heads up and
> an invitation if you have any thoughts on how better to identify TIGER
> deserts.
> >>>
> >>> thanks!
> >>>
> >>> [1]:
> http://oegeo.wordpress.com/2012/10/21/binders-full-of-tiger-deserts/
> >>> --
> >>> ian villeda
> >>> mapbox | developmentseed
> >>> https://twitter.com/ian_villeda
> >>>
> >>>
> >>> _______________________________________________
> >>> Talk-us mailing list
> >>> Talk-us at openstreetmap.org
> >>> http://lists.openstreetmap.org/listinfo/talk-us
> >>
> >> ----------------------------------------------------------------
> >> michal migurski- contact info and pgp key:
> >> sf/ca            http://mike.teczno.com/contact.html
> >>
> >>
> >>
> >>
> >>
> >> _______________________________________________
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> >> Talk-us at openstreetmap.org
> >> http://lists.openstreetmap.org/listinfo/talk-us
> >
> > Alex Barth
> > http://twitter.com/lxbarth
> > tel (+1) 202 250 3633
> >
> >
> >
> >
> >
> > _______________________________________________
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> > Talk-us at openstreetmap.org
> > http://lists.openstreetmap.org/listinfo/talk-us
> >
>
> ----------------------------------------------------------------
> michal migurski- contact info and pgp key:
> sf/ca            http://mike.teczno.com/contact.html
>
>
>
>
>
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