[postgis-users] Intersection errors out with null directed edge

[Chris Hermansen]

Thanks, Martin, I will give those a try and report back on what I find
out.

On Fri, 2007-14-09 at 10:01 -0700, Martin Davis wrote:
> Currently your only option is to run isValid on your geometry table.  It 
> will identify any geometries which are not valid. 
> 
> To see the actual nature and location of the errors you will have to 
> export them to another tool (such as JUMP or JTS TestBuilder) to see the 
> actual nature & location of the errors (Providing similar functionality 
> is on the ToDo list for PostGIS)
> 
> Martin
> 
> 
> Chris Hermansen wrote:
> > Hello again;
> >
> > So with GEOS 3.0.0RC4 the problem now becomes:
> >
> > TopologyException: EdgeRing::computePoints: found null Directed Edge
> >
> > I believe there is in fact something wrong with the data.  However the
> > TopologyException does not identify the source of the problem.
> >
> > In looking through the mailing list archives, I see questions around
> > this issue have come up in the past (eg September 2006).  I don't see
> > anyone suggesting ideas on how to find the offending data elements.
> >
> > Also, trolling through google doesn't seem to turn up anything.
> >
> > Does anyone have any ideas on how to explore the data to look for
> > problems such as this.
> >
> > Thanks in advance!
> >
> > On Thu, 2007-13-09 at 11:31 +0200, Andreas Laggner wrote:
> >   
> >> Hi Chris,
> >>
> >> as i had this errors i installed postgis with GEOS 3.0, and such an 
> >> errors never occurs again! I am not sure, but postgis 1.3.1 can be built 
> >> with GEOS 2.2 too......just run the query select postgis_full_version(); 
> >> and check your version of GEOS.
> >>
> >> cheers      Andreas
> >>
> >>
> >> Chris Hermansen schrieb:
> >>     
> >>> Hi folks;
> >>>
> >>> I had this problem today:
> >>>
> >>> AssertionFailedException: EdgeRing::computePoints: found null Directed
> >>> Edge
> >>>
> >>> I see in the archives that there are others who have suffered this, back
> >>> in 2006 and then in 2005, but there don't seem to be any offerings of
> >>> techniques to either repair the code or the data - and based on the
> >>> error above, I'm not sure which is ultimately at fault.
> >>>
> >>> Does anyone have some more up-to-date thought on this?
> >>>
> >>> I'm running postgis-1.3.1 on Ubuntu with the packaged postgresql-8.2
> >>> installed.
> >>>
> >>> Thanks in advance!
> >>>   
> >>>       
> >>     
> 
-- 
Regards,

Chris Hermansen · mailto:clh at timberline.ca
tel:+1.604.714.2878 · fax:+1.604.733.0631
Timberline Natural Resource Group · http://www.timberline.ca
401 · 958 West 8th Avenue · Vancouver BC · Canada · V5Z 1E5

C'est ma façon de parler.