[OSM-talk] What's wrong with this picture?

[David Groom]

 > ----- Original Message ----- 
> From: "Michal Migurski" <mike at stamen.com>
> To: "Talk Openstreetmap" <talk at openstreetmap.org>
> Sent: Tuesday, December 13, 2011 6:33 AM
> Subject: Re: [OSM-talk] What's wrong with this picture?
>
>
> On Dec 12, 2011, at 8:38 AM, David Groom wrote:
>
>>> I recently made some updates to the code behind the Metro Extracts
>>> (http://metro.teczno.com) that pushes the coastline files through 
>>> PostGIS
>>> and hunts down additional errors there. Many aren't interesting (nested
>>> holes) but some do lead to bugs in PostGIS and Mapnik's ability to 
>>> render
>>> tiles, self-intersections being the largest problem. I'll be updating 
>>> the
>>> site with new error shapefiles when the process stops running over the
>>> next 24 hours.
>>
>> It will be interesting to see how many errors that highlights

Mike,

thanks for the new shapefiles, they will be very useful


>
> A few sample errors:
> http://tile.stamen.com/coastline-next/preview.html#7/46.844/-86.764
>
> The two pink "2's" were identified by the coastline error checker, and (I
> think) indicate an island with part of its coastline facing away from the
> water. The three green "X's" represent self-intersections picked up by
> PostGIS, and if you zoom in more closely you'll see where they are to fix
> them. I've recently fixed up a number of self-intersections around South
> America, Mexico and the US:
> http://www.openstreetmap.org/user/migurski/edits
>
> The data for this view is linked here:
> http://metro.teczno.com/#coastline
>
> …and the stylesheets are here:
> https://github.com/migurski/Extractotron/tree/master/coastline-preview
>
> I hope to keep this view up to date regularly, though it's possible I'll
> forget from time to time. I've been watching edits near these points and
> there are a few mappers getting to them before I do:
> http://www.openstreetmap.org/user/dmgroom_ct/edits
> http://www.openstreetmap.org/user/PA94/edits

PA94 certainly seems to have got started on these quickly :)

David

>
> I've been dating blocks from versions of the coastline, they can be viewed
> here:
> http://tile.stamen.com/coastline-current/preview.html#8/46.106/-84.303
>
> -mike.
>
> ----------------------------------------------------------------
> michal migurski- mike at stamen.com
>                 415.558.1610