[postgis-users] FileGDB curves

[Andy Colson]

Yeah, I think the info is gone, because ST_LineToCurve looks the same. 
As a test I changed my map file from:

DATA 'the_geom FROM washingtonmn.streets using unique gid using srid=3857'

TO:

DATA 'the_geom FROM (select gid, fullstreet, st_LineToCurve(the_geom) as 
the_geom from washingtonmn.streets) as subq using unique gid using 
srid=3857'

And it displays the same either way.

I am using FileGDB:

ogrinfo -so WCWebDataCC.gdb/
INFO: Open of `WCWebDataCC.gdb/'
       using driver `FileGDB' successful.


The command I'm using is:

ogr2ogr -f PostgreSQL
   -lco FID=gid
   -lco SPATIAL_INDEX=OFF
   -lco GEOMETRY_NAME=the_geom
   -lco SCHEMA=washingtonmn
   -lco PRECISION=NO
   -lco DIM=2
   -t_srs EPSG:3857
   -nlt MULTILINESTRING
   'PG:dbname=gis'
   WCWebDataCC.gdb

Is the "-nlt MULTILINESTRING" doing bad things?  Its in there because 
some times I get layers marked as LINESTRING that dont convert so I just 
up them to MULTILINESTRING to get it to go.

Thanks again,

-Andy

On 11/12/2014 9:03 AM, Rémi Cura wrote:
>
> Good, you narrowed the error.
>
> The function would do it for you,
> it would convert the curved parts into curves and the straight part into
> segment,
> forming a curved polygon, which is a set of curve and segments.
>
> But I'm affraid your line must appoximate the curves to have a result.
> Your 2 first screen shots indicate that the curve information is simply
> gone.
>
> You can manually approximate curves into line in arcgis before export,
> or maybe OGR driver for arcgis support curves
> (http://www.gdal.org/drv_filegdb.html)
>
> Cheers,
> Rémi-C
>
>
>
> 2014-11-12 15:56 GMT+01:00 Andy Colson <andy at squeakycode.net
> <mailto:andy at squeakycode.net>>:
>
>     Mapserver displays it the same way:
>
>     http://testmaps.camavision.__com/map/washingtonmn?pin=16.__028.21.11.0039
>     <http://testmaps.camavision.com/map/washingtonmn?pin=16.028.21.11.0039>
>
>     The data looks like:
>
>     gis=# select st_AsText(the_geom) from streets where gid = 11517;
>     -[ RECORD 1
>     ]-----------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__------------------------------__-
>     st_astext | MULTILINESTRING((-10344354.__4038468
>     5608573.22422463,-10344363.__9860388
>     5608565.68874797,-10344398.__9885982
>     5608528.81799097,-10344438.__5518419
>     5608468.68094317,-10344404.__2129173
>     5608265.5414558,-10344355.__0291817
>     5608227.92219317,-10344239.__0250123
>     5608196.3261761,-10344230.__7760714
>     5608197.59004929,-10344187.__3835781 5608212.14184435))
>
>
>
>     So I'm assuming that its a convert problem, not a display problem.
>
>     I'm not sure how to use ST_LineToCurve.  This is a road layer and
>     everything is a MULTILINESTRING, I can't tell the straight from the
>     curves.  Can I?
>
>     Thanks,
>
>     -Andy
>
>
>
>     On 11/12/2014 3:58 AM, Rémi Cura wrote:
>
>         Hey,
>         first qgis can't deal with curve (i think),
>         so your data may be curved in your postgis but the visualisation
>         would
>         be incorrect
>            so if you are going to see some curve in qgis, you have to
>         convert the
>         curve to approximate theim using
>         http://postgis.net/docs/ST___CurveToLine.html
>         <http://postgis.net/docs/ST_CurveToLine.html>,
>         then display the geom
>         (you can do this in a view if you don't want to duplicate data)
>
>         Now if you are really really sure that data in postgis is bad (use
>         ST_AsTExt(geom) for example to see if anything look like curve)
>         Either you approximate your curve with multiline and convert it
>         back to
>         curve with postgis
>         (http://postgis.net/docs/ST___LineToCurve.html
>         <http://postgis.net/docs/ST_LineToCurve.html>)
>
>         Or you have to go the long way and pass the curves as
>         attributes, and
>         reconstruct it afterward.
>         This seems like a very bad idea.
>
>         I'm afraid curve support is very very limited in all gis tools.
>
>         Cheers,
>         Rémi-C
>
>         2014-11-12 0:00 GMT+01:00 Andy Colson <andy at squeakycode.net
>         <mailto:andy at squeakycode.net>
>         <mailto:andy at squeakycode.net <mailto:andy at squeakycode.net>>>__:
>
>              Hi All,
>
>              Not sure where the best place to ask this, so I'll start here.
>
>              I have a FileGDB that contains some curved lines, I import
>         it into
>              PostGIS and they come out as chopped off Multiline.
>
>              Here are some screen shots to help explain:
>
>              Here is arc viewing the .gdb:
>         http://testmaps.camavision.____com/arc.png
>              <http://testmaps.camavision.__com/arc.png
>         <http://testmaps.camavision.com/arc.png>>
>
>              Here is qgis viewing PostGIS:
>         http://testmaps.camavision.____com/qgis.png
>              <http://testmaps.camavision.__com/qgis.png
>         <http://testmaps.camavision.com/qgis.png>>
>
>
>              I tried to get arcCatalog to export to shapefile, but
>         something went
>              bad and I cannot even look at the .shp files.
>
>              Any hints how I can get the curve back?
>
>              Thanks for your time,
>
>              -Andy