[geos-devel] Re: geos-devel Digest, Vol 78, Issue 7

Fri Apr 10 05:46:38 EDT 2009

Hi YongHeng
the result doesn't matter : your input polygons are not valid
Pascal

2009/4/10 LiN YongHeng <bicealyh at gmail.com>

> 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 <geos-devel-request at lists.osgeo.org>
>
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>> 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 <mateusz at loskot.net>
>> Subject: Re: [geos-devel] Boost License compatibility
>> To: GEOS Development List <geos-devel at lists.osgeo.org>
>> Message-ID: <49DD1538.6050707 at loskot.net>
>> 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 <pramsey at opengeo.org>
>> Subject: Re: [geos-devel] Boost License compatibility
>> To: GEOS Development List <geos-devel at lists.osgeo.org>
>> Message-ID:
>>        <30fe546d0904081431h5cc15325kd478fb7abc81e6b at mail.gmail.com>
>> 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 <mateusz at loskot.net>
>> 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
>> > geos-devel at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/geos-devel
>> >
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Wed, 08 Apr 2009 22:41:16 +0100
>> From: Mateusz Loskot <mateusz at loskot.net>
>> Subject: Re: [geos-devel] Boost License compatibility
>> To: GEOS Development List <geos-devel at lists.osgeo.org>
>> Message-ID: <49DD19FC.7010107 at loskot.net>
>> 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 <gdt at ir.bbn.com>
>> Subject: Re: [geos-devel] Boost License compatibility
>> To: GEOS Development List <geos-devel at lists.osgeo.org>
>> Message-ID: <rmiocv6ajnb.fsf at fnord.ir.bbn.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>>
>> Mateusz Loskot <mateusz at loskot.net> 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.
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>> ------------------------------
>>
>> Message: 5
>> Date: Wed, 08 Apr 2009 23:43:41 +0100
>> From: Mateusz Loskot <mateusz at loskot.net>
>> Subject: Re: [geos-devel] Boost License compatibility
>> To: GEOS Development List <geos-devel at lists.osgeo.org>
>> Message-ID: <49DD289D.7070901 at loskot.net>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Greg Troxel wrote:
>> > Mateusz Loskot <mateusz at loskot.net> 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
>> geos-devel at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/geos-devel
>>
>> End of geos-devel Digest, Vol 78, Issue 7
>> *****************************************
>>
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