On Wed, May 2, 2012 at 3:06 PM, Judd Taylor <[email protected]>wrote:
> ... which is not GPL. Like I said, for me to use it, we had to negotiate > a license with the GPC authors. > > Free for non-commercial purposes is actually as restrictive as a > commercial license in most cases, and is certainly not a good candidate for > inclusion into the PDL core, which must be GPL (I'm pretty sure it's GPL, > but it may be some perl variant of that). > Right, it wouldn't fit in PDL's core, but it's an excellent candidate for a CPAN module, I'd say. > > > -Judd > > > ____________________________ > Judd Taylor > Software Engineer > > Orbital Systems, Ltd. > 3807 Carbon Rd. > Irving, TX 75038-3415 > > [email protected] > (972) 915-3669 x127 > ------------------------------ > *From:* Joel Berger [[email protected]] > *Sent:* Wednesday, May 02, 2012 3:02 PM > *To:* Judd Taylor > *Cc:* Chris Marshall; Steven Lembark; [email protected] > > *Subject:* Re: [Perldl] Geometry, anyone? > > Looks to be free for non-commerical use. > > http://www.cs.man.ac.uk/~toby/gpc/ > > On Wed, May 2, 2012 at 2:56 PM, Judd Taylor <[email protected]>wrote: > >> I have an interface to the GPC polygon clipping library for PDL. >> Unfortunately, GPU isn't GPL. We've had to buy a commercial license to use >> it, so it's not really a candidate for the PDL core... >> >> -Judd >> ____________________________ >> Judd Taylor >> Software Engineer >> >> Orbital Systems, Ltd. >> 3807 Carbon Rd. >> Irving, TX 75038-3415 >> >> [email protected] >> (972) 915-3669 x127 >> >> ________________________________________ >> From: Chris Marshall [[email protected]] >> Sent: Wednesday, May 02, 2012 1:55 PM >> To: Steven Lembark >> Cc: [email protected] >> Subject: Re: [Perldl] Geometry, anyone? >> >> PDL-2.4.10 and later include a pnpoly routine which may >> be of use: >> >> pdldoc pnpoly >> Module PDL::Image2D >> pnpoly >> 'points in a polygon' selection from a 2-D piddle >> >> $mask = pnpoly($x, $y, $px, $py); >> >> For a closed polygon determined by the sequence of points in {$py,$py} >> the output of pnpoly is a mask corresponding to whether or not each >> coordinate (x,y) in the set of test points, {$x,$y}, is in the interior >> of the polygon. This is the 'points in a polygon' algorithm from >> < >> http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html> >> and vectorized for PDL by Karl Glazebrook. >> >> # define a 3-sided polygon (a triangle) >> $px = pdl( 3, 20, 34 ); >> $py = pdl( 3, 20, 3 ); >> >> $img = zeros(40, 40); # create test image >> $x = $img->xvals; # get x pixel coords >> $y = $img->yvals; # get y pixel coords >> >> # $tri is 0 everywhere except for points in polygon interior >> $tri = pnpoly($x,$y,$px,$py); >> >> As for more, PDL has a lot of tools to make such >> computations work (implementable and with good >> performance). The PDL home page is a good place >> to start for more information: http://pdl.perl.org >> >> --Chris >> >> >> On Wed, May 2, 2012 at 2:49 PM, Craig DeForest >> <[email protected]> wrote: >> > There is a very nice algorithm in Preparata and Shamos ("Computational >> Geometry"). I, for one, would love to have a PDL::PlanarGeometry package >> built, to treat 2xN PDLs as collections of points on the plane. Nice >> algorithms to start with would include: >> > >> > - area >> > - hull >> > - Voronoi >> > - delaunay >> > - polygon union >> > - polygon intersection >> > - polygon clean >> > >> > >> > >> > On May 2, 2012, at 12:33 PM, Steven Lembark wrote: >> > >> >> >> >> The nice people at Oracle implement all of their OpenGIS >> >> "contained within" geometry operators using bounding boxes >> >> only. This makes it impossible to select non-rectangular >> >> areas from a map. >> >> >> >> Google has gotten me nowhere looking for a PDL geometric >> >> operator library that (ideally) works on OpenGIS format >> >> data (WKB, WKT) or at least implements a "contains" >> >> operator suitable for a point and polygon. >> >> >> >> I am not trying to plot anything, just get a boolean >> >> outcome for, say, which state contains a given lat+long >> >> or which hospital is closesest to a given point. >> >> >> >> Checking CPAN for PDL+GIS gives me PDL::GIS::Proj, which >> >> isn't about GIS and is also pretty much dead. >> >> >> >> Q: Any suggestions for an implemention for selecting >> >> which of a (largeish) list of polygons contain a >> >> given point? >> >> >> >> thanks >> >> >> >> -- >> >> Steven Lembark 3646 Flora >> Pl >> >> Workhorse Computing St Louis, MO >> 63110 >> >> [email protected] +1 888 359 >> 3508 >> >> >> >> _______________________________________________ >> >> Perldl mailing list >> >> [email protected] >> >> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl >> >> >> > >> > >> > _______________________________________________ >> > Perldl mailing list >> > [email protected] >> > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl >> >> _______________________________________________ >> Perldl mailing list >> [email protected] >> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl >> >> _______________________________________________ >> Perldl mailing list >> [email protected] >> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl >> > > > _______________________________________________ > Perldl mailing list > [email protected] > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." -- Brian Kernighan
_______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
