[Talk-us] Counties Data Import

Ian Dees ian.dees at gmail.com
Wed May 14 16:08:31 BST 2008


Wow, that is pretty ugly. The discrepency is there because the state border
source has a lower resolution than the counties border source. What's odd is
that in some spots, the county borders seem to follow land features
correctly, but in other areas they don't (
http://openstreetmap.org/?lat=40.658&lon=-76.7046&zoom=13&layers=B0FT). This
is a problem with the data source. We'll have to make a judgment call about
what to do ...

Personally, I think the "look" of a map is less important having correct
data, but I can definitely see the importance of having a visually-correct
map.

On Wed, May 14, 2008 at 9:28 AM, Ted Mielczarek <ted.mielczarek at gmail.com>
wrote:

> Just had this pointed out in #osm:
> http://tah.openstreetmap.org/Browse/?x=1109&y=1529&z=12&layer=tile
>
> What data source did you use for this? Was it from TIGER? The borders
> don't seem to line up with the state borders (from TIGER) that we
> imported previously. It looks a bit messy. :-/ I've also noticed that
> the borough boundary I imported (also from TIGER) for my town doesn't
> line up with the county borders at all:
> http://openstreetmap.org/?lat=40.69947&lon=-75.50887&zoom=16&layers=B0FT
>  The borough border seems to match reality a little better (the river
> is the county and borough boundary).
>
> -Ted
>
> On Mon, May 12, 2008 at 7:27 PM, Ian Dees <ian.dees at gmail.com> wrote:
> > I uploaded the data with the lines overlapping. I figured by combining
> the
> > ways into one with left and right tags, we are making it quite a bit
> harder
> > to query the database to determine which county any particular point is
> in.
> > Also, there would be a significant amount of work to write the import app
> to
> > do that, and I didn't think it was worth it to add time on both ends of
> the
> > workflow.
> >
> > On Mon, May 12, 2008 at 6:14 PM, Ted Mielczarek <
> ted.mielczarek at gmail.com>
> > wrote:
> >>
> >> On Fri, May 9, 2008 at 10:41 AM, Ian Dees <ian.dees at gmail.com> wrote:
> >> > Hi everyone,
> >> >
> >> > While I was trying to figure out how to divide the massive NHD dataset
> >> > into
> >> > more management pieces, I found a county boundary dataset and
> converted
> >> > it
> >> > to OSM.
> >> >
> >> > I uploaded Wisconsin and Minnesota county boundaries and submit them
> for
> >> > your review. One minor issue:
> >> >
> >> > http://tah.openstreetmap.org/Browse/?x=1036&y=1489&z=12&layer=tile
> >> > ... shows that each county is a separate, closed way in OSM. This
> means
> >> > that
> >> > at most boundaries, the dashed lines that are used to render political
> >> > boundaries are overlapping and look odd. I can't see a way around this
> >> > without losing metadata.
> >> >
> >> > If you have any opinion on how this data is represented, please let me
> >> > know.
> >> > Otherwise, I will upload the rest of the country later on this
> weekend.
> >>
> >> I looked at this data when I uploaded the state borders a while ago.
> >> The state borders I (and Adam) split by hand into non-overlapping
> >> sections, tagging them with left:state and right:state appropriately.
> >> I figured it would be too much work to do the county borders manually
> >> like that, but I didn't feel like trying to write a program to do it
> >> in an automated fashion either. I'm not really excited for having lots
> >> of overlapping borders like that, but I guess I can manually clean up
> >> the ones in my area if I care enough.
> >>
> >> -Ted
> >
> >
>
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