[pgrouting-users] PgRouting-Problems with own OSM-data

Wed May 6 21:58:18 EDT 2009

Thank you Steve!

On Wed, May 6, 2009 at 12:49 AM, Stephen Woodbridge
<woodbri at swoodbridge.com> wrote:
> Anton,
>
> I added a detailed descriptions under the tools quick link:
> http://pgrouting.postlbs.org/wiki/tools
>
> -Steve
>
>
> Anton Patrushev wrote:
>>
>> Kai, Steve,
>>
>> It sounds like a very good example of data validation and for sure
>> will be interesting for other users.
>> Can someone of you please put it to pgRouting wiki?
>>
>> Anton.
>>
>> On Sat, Apr 18, 2009 at 8:25 PM, Kai Behncke <Kai-Behncke at gmx.de> wrote:
>>>
>>> Dear users,
>>>
>>> maybe the following screenshot helps fo find out what is wrong with my
>>> geodata:
>>>
>>>
>>> http://www.selbstverwaltung-bundesweit.de/weird_numbers.png
>>>
>>>
>>>
>>> The three numbers (blcak on grey backround) show the gid of the
>>> geometry,the source-id and the target-id.
>>>
>>> The blue figure shows the id of the vertices (no dead end) and the red
>>> number is the number of the dead-end-vertices.
>>>
>>> As you cann see some are correct and some are not.
>>> This should happen at SELECT assign_vertex_id('my_table', 0.001,
>>> 'the_geom', 'gid');
>>>
>>>
>>> ....but why? I cant`t see the system of that failure?
>>>
>>> Best regards, Kai
>>> -------- Original-Nachricht --------
>>>>
>>>> Datum: Sat, 18 Apr 2009 00:57:30 +0200
>>>> Von: "Kai Behncke" <Kai-Behncke at gmx.de>
>>>> An: Stephen Woodbridge <woodbri at swoodbridge.com>,
>>>> pgrouting-users at lists.postlbs.org
>>>> Betreff: Re: [pgrouting-users] PgRouting-Problems with own OSM-data
>>>> Hi Stephen, Hi mailinglist,
>>>>
>>>> thank you very much for that hint. With that way I was able to find out
>>>> that there are far too many "dead ends" in my data, so I think this is
>>>> the
>>>> proof that it`s really a data problem?
>>>>
>>>> http://www.selbstverwaltung-bundesweit.de/too_many_dead_ends.png
>>>>
>>>> I made this test also with the victoria-data, there everything is
>>>> correct.
>>>>
>>>> To get a step further I work now with a very small dataset (just 35
>>>> geometries) (as you can see in the screenshot above) but without success
>>>> so far.
>>>>
>>>>> If you have a lot of red dots between segments
>>>>> that should be joined, you probably need to rebuild your vertices tmp
>>>>> table with a larger tolerance.
>>>>
>>>> I did that, I changed 0.001 in
>>>>
>>>> SELECT assign_vertex_id('auswahl_os', 0.001, 'the_geom', 'gid');
>>>>
>>>> with the values 0.005, 0.01, 0.05, 0.5, 5, 50 and so on
>>>>
>>>> The values <50 still show very many "dead ends". If I have higher values
>>>> then
>>>> the amount of vertices in general decreases, so a routing is also not
>>>> possible anymore, you can see it here:
>>>>
>>>>
>>>> http://www.selbstverwaltung-bundesweit.de/not_enough_vertices.png
>>>>
>>>>
>>>> Maybe the following is a hint:
>>>>
>>>> If I use
>>>> SELECT assign_vertex_id('auswahl_os', 0.001, 'the_geom', 'gid');
>>>>
>>>> with my data I get 54 entries in the vertices_tmp-table.
>>>> (an extract of the victorie-data (50 geometries) just gives 42 entries
>>>> in
>>>> vertices_tmp).
>>>>
>>>> What could be the reason that I get so many entries mith my data?
>>>>
>>>> What exactly stands the value 0.001 for?
>>>>
>>>> I really don`t understand what could be wrong with my geodata :-(
>>>>
>>>> Might it be possible that someone would have a look to these 54
>>>> geometries
>>>> (4 eyes see more than two) ??
>>>>
>>>> Puh....if I get it I will really write a huge tutorial in the
>>>> pgrouting-wiki.
>>>>
>>>> Best regards, Kai
>>>>
>>>>
>>>>
>>>> -------- Original-Nachricht --------
>>>>>
>>>>> Datum: Wed, 15 Apr 2009 13:24:21 -0500
>>>>> Von: Stephen Woodbridge <woodbri at swoodbridge.com>
>>>>> An: Kai Behncke <Kai-Behncke at gmx.de>
>>>>> CC: pgrouting-users at lists.postlbs.org
>>>>> Betreff: Re: [pgrouting-users] PgRouting-Problems with own OSM-data
>>>>> Kai,
>>>>>
>>>>> First off you probably need to build some diagnostic tools to help you
>>>>> understand the problem better, especially to help you determine if it
>>>>> is
>>>>> a data problem. I find two tools that are easy to build and help a lot.
>>>>> You can see them in action here:
>>>>> http://imaptools.com/leaddog/routing/dd.html
>>>>> Zoom into a city, open the layerswitcher and select "Just the Streets"
>>>>> and "Dead Ends"
>>>>>
>>>>> 1) create a mapfile that displays the street segments from the routing
>>>>> database and add this as an optional base layer. You might want to add
>>>>> color oneway streets a different color, but in general keep the display
>>>>> simple and probably single pixel lines. You might label the segments
>>>>> with their UID so you can go back to the database and query them in
>>>>> detail.
>>>>>
>>>>> 2) add a column cnt integer to the vertices_tmp table and update it
>>>>> with
>>>>> the count of segments that reference that node. Maybe something like
>>>>
>>>> this:
>>>>>
>>>>> alter table vertices_tmp add column cnt integer;
>>>>> update vertices_tmp set cnt=0;
>>>>> update vertices_tmp set cnt=cnt+1 where streets.source=id;
>>>>> update vertices_tmp set cnt=cnt+1 where streets.target=id;
>>>>>
>>>>> Now create a mapfile layer for points and display the vertices_tmp
>>>>>
>>>>> LAYER
>>>>>   NAME "deadends"
>>>>>   TYPE POINT
>>>>>   CONNECTIONTYPE "postgis"
>>>>>   CONNECTION ...
>>>>>   DATA ...
>>>>>   CLASSEXPRESSION "cnt"
>>>>>   CLASS
>>>>>     EXPRESSION "cnt=1"
>>>>>     STYLE
>>>>>       SYMBOL "circle"
>>>>>       SIZE 5
>>>>>       COLOR 255 0 0
>>>>>     END
>>>>>   END
>>>>>   CLASS
>>>>>     EXPRESSION "cnt>2"
>>>>>     STYLE
>>>>>       SYMBOL "circle"
>>>>>       SIZE 3
>>>>>       COLOR 0 255 0
>>>>>     END
>>>>>   END
>>>>> END
>>>>>
>>>>> This will display red dots at dead ends and green dots as good
>>>>> connections be segments. If you have a lot of red dots between segments
>>>>> that should be joined, you probably need to rebuild your vertices tmp
>>>>> table with a larger tolerance.
>>>>>
>>>>> It is very hard to debug a large black box like a router without having
>>>>> some tools that can give you some better insight as to what is going
>>>>> on.
>>>>>
>>>>> -Steve
>>>>>
>>>> --
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>>
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