[postgis-users] Difficult Problem with Polygons
Ed Linde
edolinde at gmail.com
Mon Oct 29 07:56:51 PDT 2012
Hi All,
I was trying to do this intersection between two tables, I have inserted
the selects for the two tables and the error. Also the postgis full version
information.
Is there a way to get around this problem? Is this a bug? The polygons in
both tables contain 3D points. Could this be a problem?
Cheers,
Ed
select a.id, ST_AsText(st_intersection(a.geomtext, b.geomtext)) the_tris
from small_tris a, vfaces b
where st_intersects (a.geomtext, b.geomtext);
ERROR: Error performing intersection: TopologyException: found non-noded
intersection between LINESTRING (593907 5.2196e+06, 593915 5.21961e+06) and
LINESTRING (593911 5.21961e+06, 593908 5.2196e+06) at 593908.59999999998
5219602 809.89999999999918
********** Error **********
ERROR: Error performing intersection: TopologyException: found non-noded
intersection between LINESTRING (593907 5.2196e+06, 593915 5.21961e+06) and
LINESTRING (593911 5.21961e+06, 593908 5.2196e+06) at 593908.59999999998
5219602 809.89999999999918
SQL state: XX000
SELECT PostGIS_full_version();
postgis_full_version
--------------------------------------------------------------------------------------------------------------------------------------------
-----------
POSTGIS="2.0.0alpha7SVN" GEOS="3.3.2-CAPI-1.7.2" PROJ="Rel. 4.7.1, 23
September 2009" GDAL="GDAL 1.9.0, released 2011/12/29" LIBXML="2.7.8"
USE_STATS
(1 row)
bounds=# select gen_id, ST_AsText(geomtext) from vfaces;
gen_id |
st_astext
--------+---------------------------------------------------------------------------------------------------------------------------------
7 | POLYGON Z ((593908 5219600 803,593907 5219600 818,593915 5219610
818,593911 5219610 803,593908 5219600 803))
7 | POLYGON Z ((593908 5219600 803,593899 5219600 803,593899 5219600
818,593907 5219600 818,593908 5219600 803))
7 | POLYGON Z ((593908 5219600 803,593911 5219610 803,593903 5219620
803,593899 5219620 803,593899 5219600 803,593908 5219600 803))
7 | POLYGON Z ((593899 5219620 803,593899 5219620 818,593899 5219600
818,593899 5219600 803,593899 5219620 803))
7 | POLYGON Z ((593899 5219620 803,593903 5219620 803,593912 5219620
818,593899 5219620 818,593899 5219620 803))
7 | POLYGON Z ((593912 5219620 818,593903 5219620 803,593911 5219610
803,593915 5219610 818,593912 5219620 818))
7 | POLYGON Z ((593912 5219620 818,593915 5219610 818,593907 5219600
818,593899 5219600 818,593899 5219620 818,593912 5219620 818))
16 | POLYGON Z ((593921 5219600 803,593921 5219610 803,593911 5219610
803,593908 5219600 803,593921 5219600 803))
16 | POLYGON Z ((593921 5219600 803,593921 5219600 818,593921 5219610
818,593921 5219610 803,593921 5219600 803))
16 | POLYGON Z ((593921 5219600 803,593908 5219600 803,593907 5219600
818,593921 5219600 818,593921 5219600 803))
16 | POLYGON Z ((593911 5219610 803,593921 5219610 803,593921 5219610
818,593915 5219610 818,593911 5219610 803))
16 | POLYGON Z ((593911 5219610 803,593915 5219610 818,593907 5219600
818,593908 5219600 803,593911 5219610 803))
16 | POLYGON Z ((593907 5219600 818,593915 5219610 818,593921 5219610
818,593921 5219600 818,593907 5219600 818))
18 | POLYGON Z ((593921 5219610 803,593911 5219610 803,593915 5219610
818,593921 5219610 818,593921 5219610 803))
18 | POLYGON Z ((593921 5219610 803,593921 5219620 803,593903 5219620
803,593911 5219610 803,593921 5219610 803))
18 | POLYGON Z ((593921 5219610 803,593921 5219610 818,593921 5219620
818,593921 5219620 803,593921 5219610 803))
18 | POLYGON Z ((593912 5219620 818,593915 5219610 818,593911 5219610
803,593903 5219620 803,593912 5219620 818))
18 | POLYGON Z ((593912 5219620 818,593921 5219620 818,593921 5219610
818,593915 5219610 818,593912 5219620 818))
18 | POLYGON Z ((593912 5219620 818,593903 5219620 803,593921 5219620
803,593921 5219620 818,593912 5219620 818))
(19 rows)
bounds=# select id, st_astext(geomtext) from small_tris;
id |
st_astext
----+-------------------------------------------------------------------------------------------
0 | POLYGON Z ((593890 5219590 840,593900 5219590 827,593890 5219600
817,593890 5219590 840))
1 | POLYGON Z ((593890 5219600 817,593900 5219590 827,593900 5219600
815,593890 5219600 817))
2 | POLYGON Z ((593900 5219600 815,593910 5219590 824,593910 5219600
815,593900 5219600 815))
3 | POLYGON Z ((593910 5219590 824,593900 5219600 815,593900 5219590
827,593910 5219590 824))
4 | POLYGON Z ((593910 5219600 815,593910 5219590 824,593920 5219590
842,593910 5219600 815))
5 | POLYGON Z ((593900 5219600 815,593910 5219600 815,593900 5219610
815,593900 5219600 815))
6 | POLYGON Z ((593890 5219600 817,593900 5219600 815,593900 5219610
815,593890 5219600 817))
7 | POLYGON Z ((593890 5219620 812,593890 5219610 825,593900 5219610
815,593890 5219620 812))
8 | POLYGON Z ((593890 5219630 827,593890 5219620 812,593900 5219620
841,593890 5219630 827))
9 | POLYGON Z ((593900 5219610 815,593900 5219620 841,593890 5219620
812,593900 5219610 815))
10 | POLYGON Z ((593910 5219610 819,593900 5219620 841,593900 5219610
815,593910 5219610 819))
11 | POLYGON Z ((593910 5219620 848,593900 5219630 838,593900 5219620
841,593910 5219620 848))
12 | POLYGON Z ((593900 5219620 841,593900 5219630 838,593890 5219630
827,593900 5219620 841))
13 | POLYGON Z ((593890 5219610 825,593890 5219600 817,593900 5219610
815,593890 5219610 825))
14 | POLYGON Z ((593910 5219610 819,593900 5219610 815,593910 5219600
815,593910 5219610 819))
15 | POLYGON Z ((593910 5219600 815,593920 5219600 817,593910 5219610
819,593910 5219600 815))
16 | POLYGON Z ((593920 5219600 817,593910 5219600 815,593920 5219590
842,593920 5219600 817))
17 | POLYGON Z ((593920 5219600 817,593920 5219590 842,593930 5219590
803,593920 5219600 817))
18 | POLYGON Z ((593910 5219610 819,593920 5219600 817,593920 5219610
804,593910 5219610 819))
19 | POLYGON Z ((593920 5219600 817,593930 5219600 845,593920 5219610
804,593920 5219600 817))
20 | POLYGON Z ((593930 5219600 845,593920 5219600 817,593930 5219590
803,593930 5219600 845))
21 | POLYGON Z ((593920 5219610 804,593930 5219600 845,593930 5219610
819,593920 5219610 804))
22 | POLYGON Z ((593910 5219610 819,593920 5219610 804,593920 5219620
804,593910 5219610 819))
23 | POLYGON Z ((593910 5219620 848,593920 5219620 804,593910 5219630
801,593910 5219620 848))
24 | POLYGON Z ((593910 5219620 848,593910 5219610 819,593920 5219620
804,593910 5219620 848))
25 | POLYGON Z ((593910 5219630 801,593920 5219620 804,593920 5219630
808,593910 5219630 801))
26 | POLYGON Z ((593910 5219620 848,593910 5219630 801,593900 5219630
838,593910 5219620 848))
27 | POLYGON Z ((593930 5219620 844,593920 5219630 808,593920 5219620
804,593930 5219620 844))
28 | POLYGON Z ((593930 5219630 834,593920 5219630 808,593930 5219620
844,593930 5219630 834))
29 | POLYGON Z ((593930 5219620 844,593920 5219620 804,593930 5219610
819,593930 5219620 844))
30 | POLYGON Z ((593920 5219610 804,593930 5219610 819,593920 5219620
804,593920 5219610 804))
31 | POLYGON Z ((593910 5219610 819,593910 5219620 848,593900 5219620
841,593910 5219610 819))
(32 rows)
On Mon, Oct 29, 2012 at 3:37 PM, Ed Linde <edolinde at gmail.com> wrote:
> Hi All,
> Thanks for the tips! Just another thing, when I compute the "transition
> points" on each edge (shown as red points in my pdf).
> I need to join them to make a polygon. Wondering how I can connect them
> together so that I start with a point and end on it
> to form a closed polygon?
>
> Cheers,
> Ed
>
>
> On Mon, Oct 29, 2012 at 3:03 PM, Stephen Woodbridge <
> woodbri at swoodbridge.com> wrote:
>
>> Hi Ed,
>>
>> Well if clarifies one thing at least, you can ignore Mike's st_Relate
>> because 5 is not adjacent to a linear edge, it is only adjacent to a
>> vertex, so st_touches should work fine.
>>
>> so you are looking for:
>>
>> 1. a specific triangle by id
>> 2. that intersects triangle VC
>> 3. and the triangles adjacent to triangle by id
>> 4. and those that are contained in VC
>> 5. sorted by distance to P1 limit 1
>>
>> so something like:
>>
>> select id, the_geom
>> from (select id, the_geom as adjacent
>> from triangles
>> where st_touches(the_geom,
>> (select the_geom
>> from triangles a,
>> (select the_geom as vc
>> from vc_table
>> where id='p1') b
>> where a.id=4)) c
>> order by st_distance(c.the_geom, (select the_geom
>> from points
>> where id='p1')) asc limit 1;
>>
>> Untested, but should give you a model to work with.
>>
>> -Steve W
>>
>>
>>
>> On 10/29/2012 6:57 AM, Ed Linde wrote:
>>
>>> Attached is a figure. Where the dotted line is the boundary of the
>>> voronoi cell whose
>>> generator is point P1. So triangle "4" intersects with the voronoi
>>> boundary, but we are
>>> interested in the adjacent triangles of triangle 4, which are closer to
>>> point P1.
>>> For example, triangle 5.
>>>
>>> Hope this helps.
>>> Cheers,
>>> Ed
>>>
>>> On Mon, Oct 29, 2012 at 11:50 AM, Nicolas Ribot <nicolas.ribot at gmail.com
>>> <mailto:nicolas.ribot at gmail.**com <nicolas.ribot at gmail.com>>> wrote:
>>>
>>> Could you draw a figure ?
>>>
>>> Nicolas
>>>
>>> On 29 October 2012 11:03, Ed Linde <edolinde at gmail.com
>>> <mailto:edolinde at gmail.com>> wrote:
>>> > Hi All,
>>> > Thanks for the suggestions.
>>> > For 1) I will look into how ST_touches works and see if it can
>>> pick up all
>>> > the adjacent polygons to
>>> > the one I have. And also look into Mike's suggestion on
>>> ST_relate...though I
>>> > must admit it looks
>>> > more complex.
>>> > For 2) I will try to clarify it a bit more... its harder to do
>>> without a
>>> > figure :) but here goes.
>>> >
>>> > Lets say we have a point Q which is the generator of a voronoi
>>> cell. Now I
>>> > compute the
>>> > intersection between the voronoi cell boundaries and my
>>> triangulation (Set
>>> > of polygons)
>>> > using ST_intersect. Once I have these triangles.. I say pick one
>>> triangle T
>>> > that is
>>> > intersecting the voronoi cell boundary of Q.
>>> > For all the triangles adjacent to T, I need to know which
>>> triangles are
>>> > INSIDE the voronoi
>>> > boundary (closer to Q) and which adjacent triangles are just
>>> OUTSIDE the
>>> > voronoi
>>> > boundary (farther from Q). I am basically testing for a certain
>>> property by
>>> > "shrinking" the
>>> > voronoi cell (closer to Q) and another property when "expanding"
>>> the voronoi
>>> > cell (away from Q).
>>> > Just need to make this division of triangles. Haven't thought of
>>> a nice way
>>> > to do this in postgis 2.0
>>> > So any suggestions would greatly help.
>>> >
>>> > Thanks,
>>> > Ed
>>> >
>>> > On Mon, Oct 29, 2012 at 10:15 AM, Mike Toews <mwtoews at gmail.com
>>> <mailto:mwtoews at gmail.com>> wrote:
>>> >>
>>> >> On 29 October 2012 21:33, Ed Linde <edolinde at gmail.com
>>> <mailto:edolinde at gmail.com>> wrote:
>>> >> > Hi All,
>>> >> > I need help with 2 hard problems. I store triangles in a table
>>> as
>>> >> > POLYGON.
>>> >> >
>>> >> > 1. I want to know for a given triangle, which triangles share
>>> an edge
>>> >> > (adjacent) with this triangle.
>>> >>
>>> >> Sounds like you have a finite element mesh with nodes and
>>> elements.
>>> >> You can use ST_Relate with pattern 'FF2F11212' to pick out
>>> elements
>>> >> that share the same edge. This DE-9-IM is sort-of a custom
>>> ST_Touches,
>>> >> but only takes linear boundary overlaps. So if you have a table
>>> >> "elements", and you want to find ones that touch ID 567:
>>> >>
>>> >> SELECT elements.*
>>> >> FROM elements, elements as e
>>> >> WHERE e.id <http://e.id> = 567 AND
>>>
>>> >> ST_Relate(elements.geom, e.geom, 'FF2F11212');
>>> >>
>>> >> I'm not certain about your second question.
>>> >>
>>> >> -Mike
>>> >> ______________________________**_________________
>>> >> postgis-users mailing list
>>> >> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> >
>>>
>>> >> http://postgis.refractions.**net/mailman/listinfo/postgis-**
>>> users <http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>> >
>>> >
>>> >
>>> > ______________________________**_________________
>>> > postgis-users mailing list
>>> > postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> >
>>>
>>> > http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>> >
>>> ______________________________**_________________
>>> postgis-users mailing list
>>> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> >
>>>
>>> http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>>
>>>
>>>
>>>
>>> ______________________________**_________________
>>> postgis-users mailing list
>>> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>>> http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>>
>>>
>> ______________________________**_________________
>> postgis-users mailing list
>> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20121029/c7faac82/attachment.html>
More information about the postgis-users
mailing list