From sim at gis-lab.info  Sat Sep  6 18:22:38 2008
From: sim at gis-lab.info (Maxim Dubinin)
Date: Sat, 6 Sep 2008 17:22:38 -0500
Subject: [Osmlib-user] Skipping unclosed polygons
Message-ID: <1113163247.20080906172238@gis-lab.info>

Hi

I'm trying to figure out what is wrong with my OSM->shapefile
(polygons) processing using OSMLib. Here is my rule-file:

setup :Shp do
    polygon :waterway_a do
                name 'waterway_a'
                string :Boat, 4
                string :Int_name, 20
                string :Name, 20
                string :Natural, 20
        end
end

ways do
    if waterway
        :waterway_a << {:Name => name, :Int_name => int_name, :Boat => boat}
    end
end


The error message is the following:

> /usr/local/lib/ruby/gems/1.8/gems/osmlib-base-0.1.3/lib/OSM/objects.rb:493:in
> `polygon': way is not closed so it can't be represented as Polygon (OSM::NotClosedError)

As I understood, OSM XML doesn't have explicit definition for polygon
rather then just closed polyline. But even if one of my waterways is not
closed, process stops and shapefile has 0 records. May be it is wiser to
just skip the object which is not closed?

I can provide example of osm-file if this would help. Thanks.

Maxim


From jochen at remote.org  Sun Sep  7 12:45:38 2008
From: jochen at remote.org (Jochen Topf)
Date: Sun, 7 Sep 2008 18:45:38 +0200
Subject: [Osmlib-user] Skipping unclosed polygons
In-Reply-To: <1113163247.20080906172238@gis-lab.info>
References: <1113163247.20080906172238@gis-lab.info>
Message-ID: <20080907164537.GA32685@eldorado.topf.org>

On Sat, Sep 06, 2008 at 05:22:38PM -0500, Maxim Dubinin wrote:
> I'm trying to figure out what is wrong with my OSM->shapefile
> (polygons) processing using OSMLib. Here is my rule-file:
> 
> setup :Shp do
>     polygon :waterway_a do
>                 name 'waterway_a'
>                 string :Boat, 4
>                 string :Int_name, 20
>                 string :Name, 20
>                 string :Natural, 20
>         end
> end
> 
> ways do
>     if waterway
>         :waterway_a << {:Name => name, :Int_name => int_name, :Boat => boat}
>     end
> end
> 
> 
> The error message is the following:
> 
> > /usr/local/lib/ruby/gems/1.8/gems/osmlib-base-0.1.3/lib/OSM/objects.rb:493:in
> > `polygon': way is not closed so it can't be represented as Polygon (OSM::NotClosedError)
> 
> As I understood, OSM XML doesn't have explicit definition for polygon
> rather then just closed polyline. But even if one of my waterways is not
> closed, process stops and shapefile has 0 records. May be it is wiser to
> just skip the object which is not closed?
> 
> I can provide example of osm-file if this would help. Thanks.

Generally waterway=* is a line feature. So you shouldn't expect it to contain
polygons. Use natural=water for lakes.

That beeing said, try the following: In OSM/Export/Shp.rb change the
line
    rescue OSM::GeometryError
into
    rescue OSM::GeometryError, OSM::NotClosedError

That should ignore this error.

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298