Hi YongHeng the result doesn't matter : your input polygons are not valid Pascal
2009/4/10 LiN YongHeng <[email protected]> > Hello everyone, > I have a question about GEOSUnion(). > I give value to g1 and g2 like below: > GEOSGeom g1 = "POLYGON ((1 3, 1 3, 1 6, 1 6, 1 3))" and GEOSGeom g2 = > "POLYGON ((1 3, 1 3, 1 6, 1 6, 1 3))" , but if I make union operation > like GEOSGeom g3 = > GEOSUnion(g1, g2), it give me result like "GEOMETRYCOLLECTION EMPTY". > Does anyone can tell me why? > > > > 2009/4/10 <[email protected]> > >> Send geos-devel mailing list submissions to >> [email protected] >> >> To subscribe or unsubscribe via the World Wide Web, visit >> http://lists.osgeo.org/mailman/listinfo/geos-devel >> or, via email, send a message with subject or body 'help' to >> [email protected] >> >> You can reach the person managing the list at >> [email protected] >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of geos-devel digest..." >> >> >> Today's Topics: >> >> 1. Re: Boost License compatibility (Mateusz Loskot) >> 2. Re: Boost License compatibility (Paul Ramsey) >> 3. Re: Boost License compatibility (Mateusz Loskot) >> 4. Re: Boost License compatibility (Greg Troxel) >> 5. Re: Boost License compatibility (Mateusz Loskot) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Wed, 08 Apr 2009 22:20:56 +0100 >> From: Mateusz Loskot <[email protected]> >> Subject: Re: [geos-devel] Boost License compatibility >> To: GEOS Development List <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Paul Ramsey wrote: >> > Since you're talking about taking a small snippet of LGPL and putting >> > it into a larger chunk of Boost, probably you will get no definitive >> > answer, since it hinges on whether your new combined result is a >> > "derived work" (in which case it's LGPL) or not (in which case it can >> > be Boost). The "safe" black-and-white answer is that combining >> > anything from a *GPL project with another compatibly-licensed project >> > creates a *GPL resultant. >> >> All this makes sense and seems to be best approach. Thanks! >> >> Slightly changing my original question. >> Let's assume no code is copied. >> Is it safe to "translate" or let's say rewrite some parts of >> implementation of algorithms available in GEOS, using different >> types, different idioms, different C++ constructions, etc. >> and license such work under the terms of Boost License? >> >> Best regards, >> >> p.s. I understand that the best answer is >> probably "Ask your lawyer!", so sorry for bothering >> if it's OT here. >> >> -- >> Mateusz Loskot, http://mateusz.loskot.net >> Charter Member of OSGeo, http://osgeo.org >> >> >> ------------------------------ >> >> Message: 2 >> Date: Wed, 8 Apr 2009 14:31:55 -0700 >> From: Paul Ramsey <[email protected]> >> Subject: Re: [geos-devel] Boost License compatibility >> To: GEOS Development List <[email protected]> >> Message-ID: >> <[email protected]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Definitely an "ask your lawyer". Our feeling when porting JTS to C++ >> was that the port was still a "derived work" and should retain the >> LGPL license of the original work. However, that was merely a feeling, >> I have no idea where the grey areas lie in things like algorithm >> porting. >> >> P. >> >> On Wed, Apr 8, 2009 at 2:20 PM, Mateusz Loskot <[email protected]> >> wrote: >> > Paul Ramsey wrote: >> >> Since you're talking about taking a small snippet of LGPL and putting >> >> it into a larger chunk of Boost, probably you will get no definitive >> >> answer, since it hinges on whether your new combined result is a >> >> "derived work" (in which case it's LGPL) or not (in which case it can >> >> be Boost). The "safe" black-and-white answer is that combining >> >> anything from a *GPL project with another compatibly-licensed project >> >> creates a *GPL resultant. >> > >> > All this makes sense and seems to be best approach. Thanks! >> > >> > Slightly changing my original question. >> > Let's assume no code is copied. >> > Is it safe to "translate" or let's say rewrite some parts of >> > implementation of algorithms available in GEOS, using different >> > types, different idioms, different C++ constructions, etc. >> > and license such work under the terms of Boost License? >> > >> > Best regards, >> > >> > p.s. I understand that the best answer is >> > probably "Ask your lawyer!", so sorry for bothering >> > if it's OT here. >> > >> > -- >> > Mateusz Loskot, http://mateusz.loskot.net >> > Charter Member of OSGeo, http://osgeo.org >> > _______________________________________________ >> > geos-devel mailing list >> > [email protected] >> > http://lists.osgeo.org/mailman/listinfo/geos-devel >> > >> >> >> ------------------------------ >> >> Message: 3 >> Date: Wed, 08 Apr 2009 22:41:16 +0100 >> From: Mateusz Loskot <[email protected]> >> Subject: Re: [geos-devel] Boost License compatibility >> To: GEOS Development List <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Paul Ramsey wrote: >> > Definitely an "ask your lawyer". Our feeling when porting JTS to C++ >> > was that the port was still a "derived work" and should retain the >> > LGPL license of the original work. However, that was merely a feeling, >> > I have no idea where the grey areas lie in things like algorithm >> > porting. >> >> Right, I have similar feeling. >> >> Thanks for help! >> >> Best regards, >> -- >> Mateusz Loskot, http://mateusz.loskot.net >> Charter Member of OSGeo, http://osgeo.org >> >> >> ------------------------------ >> >> Message: 4 >> Date: Wed, 08 Apr 2009 18:02:48 -0400 >> From: Greg Troxel <[email protected]> >> Subject: Re: [geos-devel] Boost License compatibility >> To: GEOS Development List <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset="us-ascii" >> >> >> Mateusz Loskot <[email protected]> writes: >> >> > The question is like this: >> > >> > Can I copy lines 10-30 from GEOS source file a.cpp to project X which >> > is licensed under the terms of Boost License? >> >> If those lines are deemed to be non-trivial - and the rule of them is >> that 10 or more lines are definitely non-trivial - then no, because you >> have a derived work and can't distribute the LGPL code under the Boost >> License. If you read one line and write something to do a similar >> algorithm but differently, almost certainly it's not a derived work and >> the licnense of the inspirational work doesn't matter. The middle >> ground is hard and standard advice is not to skate near the edge of thin >> ice. >> >> > There is an existing code, project X licensed under Boost License. >> > If I copy some work based on LGPL and include it in the X, >> > can I still distribute X under the terms of Boost License? >> >> Definitely not. >> >> >> It's pretty clear the boost people would reject including LPGL code >> >> in boost, if that's what you are asking. >> > >> > And this is something that is not clear or better, not obvious to me. >> >> >From reading their analysis of licenses, it seems clear to me that Boost >> wants to allow proprietary use of boost. This is the same licensing >> goal as the BSDs, and it's different from the FSF goal. >> -------------- next part -------------- >> A non-text attachment was scrubbed... >> Name: not available >> Type: application/pgp-signature >> Size: 193 bytes >> Desc: not available >> Url : >> http://lists.osgeo.org/pipermail/geos-devel/attachments/20090408/da027928/attachment-0001.bin >> >> ------------------------------ >> >> Message: 5 >> Date: Wed, 08 Apr 2009 23:43:41 +0100 >> From: Mateusz Loskot <[email protected]> >> Subject: Re: [geos-devel] Boost License compatibility >> To: GEOS Development List <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Greg Troxel wrote: >> > Mateusz Loskot <[email protected]> writes: >> > >> >> The question is like this: >> >> >> >> Can I copy lines 10-30 from GEOS source file a.cpp to project X which >> >> is licensed under the terms of Boost License? >> > >> > If those lines are deemed to be non-trivial - and the rule of them is >> > that 10 or more lines are definitely non-trivial - then no, because you >> > have a derived work and can't distribute the LGPL code under the Boost >> > License. If you read one line and write something to do a similar >> > algorithm but differently, almost certainly it's not a derived work and >> > the licnense of the inspirational work doesn't matter. The middle >> > ground is hard and standard advice is not to skate near the edge of thin >> > ice. >> >> Yes, this is best recommendation. >> >> >>> It's pretty clear the boost people would reject including LPGL code >> >>> in boost, if that's what you are asking. >> >> And this is something that is not clear or better, not obvious to me. >> > >> > From reading their analysis of licenses, it seems clear to me that Boost >> > wants to allow proprietary use of boost. This is the same licensing >> > goal as the BSDs, and it's different from the FSF goal. >> >> Right, good point. >> >> Thanks to all for help in understanding the issue! >> >> Best regards, >> -- >> Mateusz Loskot, http://mateusz.loskot.net >> Charter Member of OSGeo, http://osgeo.org >> >> >> ------------------------------ >> >> _______________________________________________ >> geos-devel mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/geos-devel >> >> End of geos-devel Digest, Vol 78, Issue 7 >> ***************************************** >> > > > _______________________________________________ > geos-devel mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/geos-devel >
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