ST_HasArc() should do what you want
On Tue, May 5, 2015 at 1:52 AM, Andrea Aime <andrea.a...@geo-solutions.it> wrote: > Hi, > I have some generic build of code that are building queries to postgis > includingthe st_simplify function, e.g: > > select st_simplify(geometry, tolerance) from mytable where ... > > This is done to optimize data transfer and overall performance when doing > map rendering, we just get the > geometries as "complex" as we need them to. > > However, I've found out that the function does not support curved > geometries, all will throw an error if it > encounters one of them, e.g.: > >> select st_simplify(geometry, 0.1) from curves; > ERROR: lwgeom_simplify: unsupported geometry type: CircularString > > Curved geometries are often representing a small percentage of the > geometries, so I would like > to keep on simplifying the geometries made of straight segments, while > skipping simplification > on the curved ones, so I'm looking for a way to quickly and unobstrusively > check if geometry > has curved portions inside of it. > > So far I've come up with this, but it's not simple, unobstrusive, probably > not so fast due to string > comparisons, and not general (what if I stumble into a geometry collection > that does contain > curve elements for example?): > > select case geometrytype(geometry) when 'CIRCULARSTRING' then geometry > when 'COMPOUNDCURVE' then geometry > when 'CURVEPOLYGON' then geometry > when 'MULTISURFACE' then geometry > when 'MULTICURVE' then geometry > else st_simplify(geometry,0.1) > end > from curves; > > Can anybody suggest a better way, that would not require us to have the end > user tell > us if a table mixes in curve bits, or not? > > Cheers > Andrea > > -- > == > GeoServer Professional Services from the experts! Visit > http://goo.gl/NWWaa2 for more information. > == > > Ing. Andrea Aime > @geowolf > Technical Lead > > GeoSolutions S.A.S. > Via Poggio alle Viti 1187 > 55054 Massarosa (LU) > Italy > phone: +39 0584 962313 > fax: +39 0584 1660272 > mob: +39 339 8844549 > > http://www.geo-solutions.it > http://twitter.com/geosolutions_it > > AVVERTENZE AI SENSI DEL D.Lgs. 196/2003 > > Le informazioni contenute in questo messaggio di posta elettronica e/o nel/i > file/s allegato/i sono da considerarsi strettamente riservate. Il loro > utilizzo è consentito esclusivamente al destinatario del messaggio, per le > finalità indicate nel messaggio stesso. Qualora riceviate questo messaggio > senza esserne il destinatario, Vi preghiamo cortesemente di darcene notizia > via e-mail e di procedere alla distruzione del messaggio stesso, > cancellandolo dal Vostro sistema. Conservare il messaggio stesso, divulgarlo > anche in parte, distribuirlo ad altri soggetti, copiarlo, od utilizzarlo per > finalità diverse, costituisce comportamento contrario ai principi dettati > dal D.Lgs. 196/2003. > > > > The information in this message and/or attachments, is intended solely for > the attention and use of the named addressee(s) and may be confidential or > proprietary in nature or covered by the provisions of privacy act > (Legislative Decree June, 30 2003, no.196 - Italy's New Data Protection > Code).Any use not in accord with its purpose, any disclosure, reproduction, > copying, distribution, or either dissemination, either whole or partial, is > strictly forbidden except previous formal approval of the named > addressee(s). If you are not the intended recipient, please contact > immediately the sender by telephone, fax or e-mail and delete the > information in this message that has been received in error. The sender does > not give any warranty or accept liability as the content, accuracy or > completeness of sent messages and accepts no responsibility for changes > made after they were sent or for other risks which arise as a result of > e-mail transmission, viruses, etc. > > > ------------------------------------------------------- > > _______________________________________________ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users