[R-sig-Geo] Status of gpclib license

[Nicholas Lewin-Koh]

Hi,
Thanks, I must be remembering something else then. I hope I am not APOE4
+/+.

Nicholas

On Sun, 17 Jan 2010 17:44 +0100, "Edzer Pebesma"
<edzer.pebesma at uni-muenster.de> wrote:
> Nicholas,
> 
> this is unlikely; if true, the author would have done well to update his 
> software page http://www.cs.manchester.ac.uk/~toby/alan/software/ and 
> the corresponding wikipedia entry, 
> http://en.wikipedia.org/wiki/GPC_General_Polygon_Clipper_Library
> 
> Even (some) universities can these days be very picky with licensing 
> when someone at the administration level smells money revenues from 
> software developed by one of the employees; they might claim that 
> anything produced by the employees in work time is owned by the
> university.
> 
> Best wishes,
> --
> Edzer
> 
> Nicholas Lewin-Koh wrote:
> > Hi Roger,
> > I thought I remembered that at some point you had contacted the author
> > of gpclib and gotten permission to release the package under gpl. Has
> > that changed or is senility completely catching up with me.
> >
> > Nicholas
> >
> >
> >   
> >> Date: Fri, 15 Jan 2010 20:00:30 +0100 (CET)
> >> From: Roger Bivand <Roger.Bivand at nhh.no>
> >> To: rick reeves <reeves at nceas.ucsb.edu>
> >> Cc: "r-sig-geo at stat.math.ethz.ch" <r-sig-geo at stat.math.ethz.ch>
> >> Subject: Re: [R-sig-Geo] Alternate methods: Polygon Algebra / Polygon
> >> 	Overlay with R Spatial objects..
> >> Message-ID: <alpine.LRH.2.00.1001151932080.18465 at reclus.nhh.no>
> >> Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII
> >>
> >> On Fri, 15 Jan 2010, rick reeves wrote:
> >>
> >>     
> >>> Hello List:
> >>>
> >>> I have been reviewing techniques within R for performing the GIS-like 
> >>> operation 'polygon algebra' (computing the union and intersection of 
> >>> polygons within two SpatialPolygonDataFrame objects). The goal is to 
> >>> combine two polygon data frames, to produce a new polygon data frames 
> >>> that contain the union or intersection of the two input sets.
> >>>
> >>> Thus far, the only method that I have found for this is the 
> >>> combinePolys() method within the PBSmapping package. The PBSmapping 
> >>> routines work well, but require the transformation out of the 
> >>> SpatialXXXDataFrame classes.
> >>>       
> >> For union, aka dissolve, see unionSpatialPolygons() in maptools. Perhaps 
> >> better, don't look yet. The underlying problem is the license of the 
> >> gpclib package, which should be avoided. The reason for attention to 
> >> package licenses is that CRAN is getting very large, and taking 
> >> responsibility for distributing non-free software through package 
> >> dependencies needs to be automated. So GPL and other free packages should 
> >> not depend on or suggest non-free packages, because users (including 
> >> commercial users) may not be aware that they are using packages with 
> >> non-free licences. Some of these users already block the installation of 
> >> free packages with "upstream" non-free dependencies, and more will do so 
> >> in the future.
> >>
> >> One solution is the R-Forge rgeos package, which I'm working on.
> >>
> >> https://r-forge.r-project.org/projects/rgeos/
> >>
> >> Before long, again thanks to Uwe Ligges and others, we should have a 
> >> working production line for Windows binary packages with GEOS 3.1.1 
> >> included. Linux distributions have binaries or can install from source; 
> >> OSX has a Kyngchaos framework to handle the external dependency on GEOS.
> >>
> >> rgeos has unionSpatialPolygonsGEOS(), which, when rgeos reaches CRAN,
> >> will 
> >> be used by maptools in unionSpatialPolygons() if rgeos is available.
> >>
> >> GEOS has the necessary functions to do what you would like, but someone 
> >> has to write the R and C code and add it to rgeos. The current 
> >> SpatialLinesIntersections() function returns a SpatialPointsDataFrame 
> >> object with the IDs if the intersecting lines, but more is needed for 
> >> SpatialPolygons intersection. The handling of the data frame variables is 
> >> far from obvious too - just copying across count or rate variables isn't 
> >> appropriate. Most likely the handling of the data slots would have to be 
> >> done by hand for the new SpatialPolygons objects based on the
> >> intersecting 
> >> ID values.
> >>
> >> R-Forge has the possibility for new developers to join projects ...
> >>
> >> Hope this helps,
> >>
> >> Roger
> >>
> >>     
> >>> The overlay() method within sp seems like the best routine for this job as it
> >>> performs intersection operations on pairs of Spatial objects, but it
> >>> does not appear to operate on two SpatialPolygonDataFrame objects.
> >>> So I have not tried to use it for this.
> >>>
> >>> Do other packages contain polygon algebra routines that operate on the 
> >>> Spatial classes?
> >>> If not, are there any alternatives to the PBSmapping methods?
> >>>
> >>> Thanks,
> >>> Rick R
> >>>
> >>>
> >>>
> >>>
> >>>       
> >> -- 
> >> Roger Bivand
> >> Economic Geography Section, Department of Economics, Norwegian School of
> >> Economics and Business Administration, Helleveien 30, N-5045 Bergen,
> >> Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
> >> e-mail: Roger.Bivand at nhh.no
> >>
> >>
> >>
> >> ------------------------------
> >>
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> >>
> >>
> >> End of R-sig-Geo Digest, Vol 77, Issue 13
> >> *****************************************
> >>     
> >
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> >   
> 
> -- 
> Edzer Pebesma
> Institute for Geoinformatics (ifgi), University of Münster 
> Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 
> 8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de 
> http://www.52north.org/geostatistics      e.pebesma at wwu.de
>