I'll do some more checks to see if ogr2ogr really is the problem.
Simon
Sent from BlueMail
On 22 Jan. 2019, 15:22, at 15:22, Martin Davis wrote:
>Perhaps log this as an OGR issue [1]? Probably need to bisect the
>problem
>a bit more though (e.g. reduce the input to a single failing polygon).
Perhaps log this as an OGR issue [1]? Probably need to bisect the problem
a bit more though (e.g. reduce the input to a single failing polygon).
[1] https://github.com/OSGeo/gdal/issues
On Mon, Jan 21, 2019 at 7:06 PM Simon Greener
wrote:
> I replaced the shapefile load script dropping ogr
I replaced the shapefile load script dropping ogr2ogr in favor of shp2pgshp.
This appears to have given me clean multipolygons as nothing was reported by
the following:
select ST_ISValidReason(a.geog4326::geometry)
from data.osm_county as a
where ST_IsValidReason(a.geog4326::geometry) <> 'Va
Thanks.
I couldn't see how this would help as this is structural not mathematical.
But I am trying to bring the parts back together.
S
On Tue, 22 Jan 2019 10:01:36 +1100, Martin Davis wrote:
Could the problem be the use of the ogr2ogr option -nlt POLYGON ? Some of the
input geometries are
Try the ireland.sql file again.
I used Paul's suggested SQL.
S
On Tue, 22 Jan 2019 09:39:25 +1100, Martin Davis wrote:
Not much help, I'm afraid. I need the geometry in WKBHex. Not sure offhand
how to get that out of PostGIS.
Just post the WKT and let's see what that looks like.
On Mon, J
I'm didn't load into geometry, I used ogr2ogr to load into geography. All work
to date has been ok except now I want to aggregate union the polygon parts of
bounties with multiple polygon parts. ST_Union is not geographic aware hence
all the trouble.
Using geometry as the load target does not a
Could the problem be the use of the ogr2ogr option -nlt POLYGON ? Some of
the input geometries are multipolygons, and it sounds like the way to
handle this with ogr2ogr is to use GEOMETRY or PROMOTE_TO_MULTI [1][2]
[1] https://www.gdal.org/ogr2ogr.html
[2] https://gis.stackexchange.com/a/195223
Just ’select geom’ will return the extended hexwkb (which we should have JTS
support as a matter of convenience). If you need pure standard hex wkb, then
select encode(st_asbinary(geom), ‘hex’)
will do that
P
> On Jan 21, 2019, at 2:39 PM, Martin Davis wrote:
>
> Not much help, I'm afraid.
> On Jan 21, 2019, at 1:46 PM, Simon Greener wrote:
>
> Thanks Paul.
>
> However, I get the same number of distinct st_isvalidreason results.
Something is awry here, because I get only 'Valid Geometry’ as a validity check
result… I loaded your shape file, I have 42 irish counties, I didn’t e
Not much help, I'm afraid. I need the geometry in WKBHex. Not sure
offhand how to get that out of PostGIS.
Just post the WKT and let's see what that looks like.
On Mon, Jan 21, 2019 at 1:52 PM Simon Greener
wrote:
> Try here for an example:
>
> https://www.dropbox.com/s/n234bc6i5hj7y4o/Irela
Try here for an example:
https://www.dropbox.com/s/n234bc6i5hj7y4o/Ireland.sql?dl=0___
postgis-users mailing list
postgis-users@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/postgis-users
Thanks Paul.
However, I get the same number of distinct st_isvalidreason results.
Is there anything I can do with ogr2ogr when loading to help?
Simon
On Tue, 22 Jan 2019 08:34:02 +1100, Paul Ramsey
wrote:
+proj=gnom +lat_0=53.35 +lon_0=-6.26 +x_0=0 +y_0=0 +ellps=WGS84 +units=m
+no_defs
> On Jan 21, 2019, at 1:28 PM, Simon Greener wrote:
>
> I can't find a suitable gnomic srid for PostGIS.
>
You’re going to want one centred on Ireland, not the pole, and I think maybe
it’s wanting a geodetic basis, try this:
+proj=gnom +lat_0=53.35 +lon_0=-6.26 +x_0=0 +y_0=0 +ellps=WGS84 +
Can you post the WKB of one of the failing geometries, from the loaded
data? It's best to look at the exact input causing the problem.
On a side note, I did notice that when the polygons were merged (using JTS,
which works fine), there is only one very small hole in the result [1]. It
seems to c
Paul,
I can't find a suitable gnomic srid for PostGIS.
I have tried this:
INSERT INTO spatial_ref_sys (srid, proj4text) VALUES (55000, '+proj=gnom
+lat_0=90 +lon_0=-7.646288');
but I get this when I use ST_Transform.
UPDATE data.osm_county SET geom55000 = ST_Transform(geog4326::geometry,5500
Not really sure that’s the answer… I’d much rather see work on geodetic edges
in GEOS
P
> On Jan 21, 2019, at 1:20 PM, Darafei Komяpa Praliaskouski
> wrote:
>
> If someone is willing, there is an old Geography Overlays patch that needs
> lots of love: https://github.com/postgis/postgis/pull/
If someone is willing, there is an old Geography Overlays patch that needs
lots of love: https://github.com/postgis/postgis/pull/191
On Tue, Jan 22, 2019 at 12:13 AM Paul Ramsey
wrote:
>
>
> > On Jan 21, 2019, at 1:00 PM, Simon Greener
> wrote:
> >
> > When a geography is casted to geometry for
> On Jan 21, 2019, at 1:00 PM, Simon Greener wrote:
>
> When a geography is casted to geometry for use in the aggregate form of
> ST_Union (or other commands such as ST_Within) is the processing done
> assuming the data is projected even when geodetic?
All processing of geometry make cartesi
The shapefile (from OSM) can be accessed here:
https://www.dropbox.com/s/jbptp3ycmc8cqzi/gis_osm_county_a_free_1.rar?dl=0
The command used to load is:
ogr2ogr -overwrite -progress -skipfailures -a_srs "EPSG:4326" ^
-f "PostgreSQL" PG:"dbname='gisdb' host='localhost' port='5432'
user='postgre
Simon, can you post one (or more) of the geographies which are being
reported as invalid when you run *select distinct
st_isvalidreason(a.geog4326::geometry) *?
It's certainly possible for reprojection to introduce invalidities, due to
geodesic/straight line issue. I'm actually surprised this d
If it’s just Ireland, transform to a good Irish projection after casting to
geometry. For maximum awsomeness, transform to gnomonic, in which great circles
are represented as straight lines… then even all the introduced points will be
at the correct geographic locations. Works for smaller areas,
Hi Simon,
I assume, you are trying to get this all done in one query, right? Did you try
to throw ST_MakeValid into the mix? Like:
ST_Transform(ST_Union(ST_MakeValid(ST_Transform(a.geog4326::geometry, 3857))),
4326)::geography
Regards,
Birgit
Von: "Simon Greener"
An: "PostGIS Users D
22 matches
Mail list logo
