Hi Giuseppe thanks for looking into this. Do you think it's worth filling out a bug report since the nearestNeighbor method does not the keep the promise or is this the normal behaviour of a spatial index based method?
regards Stefan mit freundlichem Gruss Stefan Ziegler ----- Originalnachricht ----- Von: "Giuseppe Sucameli" <sucam...@faunalia.it> Gesendet: Mit, 27.10.2010 17:30 An: "Ziegler Stefan" <stefan.zieg...@bd.so.ch> Cc: "Jim Hammack" <hamm...@gotslack.org> ; qgis-user <qgis-user@lists.osgeo.org> Betreff: Re: AW: Re: Fwd: [Qgis-user] QGIS "Near" Hi Stefan, your workaround works fine in my case! I looked at the QgsSpatialIndex code and I have bad news... It uses the bounding box of the geometries! This means that your workaround can work in a lot of cases but not in all cases, e.g. if you have more than N geometries (10 considering your workaround), ones inside each other. Cheers. On Tue, Oct 26, 2010 at 6:47 PM, Ziegler Stefan <stefan.zieg...@bd.so.ch> wrote: Hi Giuseppe I wrote a little workaround. Could you please update to 0.0.6 and check it with your test case? Thanks. regards Stefan mit freundlichem Gruss Stefan Ziegler ----- Originalnachricht ----- Von: "Giuseppe Sucameli" <sucam...@faunalia.it> Gesendet: Mon, 25.10.2010 14:09 An: "Ziegler Stefan" <stefan.zieg...@bd.so.ch> Cc: "Jim Hammack" <hamm...@gotslack.org> ; qgis-user <qgis-user@lists.osgeo.org> Betreff: Re: AW: Re: Fwd: [Qgis-user] QGIS "Near" Hi all, two days ago I wrote a similar plugin for a LD talk in Pisa. I was unaware of the QgsSpatialIndex class (seems there's no documentation about it in the online QGis API pages or maybe I missed it) so I wrote a simple loop to find the closest feature. Now I tried also the Nearest plugin and they are different behavior! See the scheenshots [1] [2]. AFAICS, Nearest select a wrong polygon. I see the plugin's code and I think it could a QgsSpatialIndex bug, but it could be also the normal behaviour (I didn't found its documentation on the API pages so I don't know). I'm going to add my plugin (ClosestFeatureFinded) to the Faunalia repo so you can try it and check the different behavior. I hope this can help to find the bug (if any). If you confirm it, I'll fill a bug report. Cheers. [1] http://img87.imageshack.us/img87/3232/nearest.jpg [2] http://img64.imageshack.us/img64/2066/closest.jpg On Fri, Oct 22, 2010 at 9:19 AM, Ziegler Stefan <stefan.zieg...@bd.so.ch> wrote: there is some strange behaviour when using it with polygon features (at least I think it's a bit strange): sometimes when you click into a polygon I would expect that it selects the polygon I clicked into but it selects an adjacent polygon. This is probably due to the nearestNeighbor method of the spatial index. Since the two neighboring polygons share a common border the distance would be equal but the spatial index does not check if the coordindates of the mouse click lies within one of the two polygons. regards Stefan mit freundlichem Gruss Stefan Ziegler ----- Originalnachricht ----- Von: "Jim Hammack" <hamm...@gotslack.org> Gesendet: Don, 21.10.2010 19:20 An: "Ziegler Stefan" <stefan.zieg...@bd.so.ch> Cc: qgis-user <qgis-user@lists.osgeo.org> Betreff: Re: AW: Re: Fwd: [Qgis-user] QGIS "Near" Stefan, I was looking for the same functionality as Zoran so have also been working with your "Nearest" plugin. It is exactly what I need and seems to work well. Thanks! Jim On 10/20/2010 01:54 PM, Ziegler Stefan wrote: Hi Zoran I had some time left, took all my code snippets and also the one from Carson. Please try the plugin "Nearest" that should cover your example 1: http://www.catais.org/qgis/plugins.xml regards Stefan -----Ursprüngliche Nachricht----- Von: Zoran Jankovic [mailto:zoran.janko...@zisis.hr] Gesendet am: Mittwoch, 20. Oktober 2010 19:21 An: qgis-user Betreff: Re: Fwd: [Qgis-user] QGIS "Near" Hi Joe, On Wed, Oct 20, 2010 at 5:06 PM, Joe Larson <joela...@gmail.com> wrote: Does the function 'snapWithContext' http://doc.qgis.org/head/classQgsVectorLayer.html#733b974dce13d587e05cf3d4fc24f208 which "Snaps to segment or vertex within given tolerance." seem like what you're looking for? I came across it while trying to get Quantum Navigator working recently...seemed relative, but I'm no expert! This is similar to the mentioned solution with selecting by radius, or changing the tolerance of ID tool. Close, but no cigar. Since this is not very urgent, I've decided to continue pursuing that outlined solution Carson gave, and write a plugin i Python based on that. Since I actually never used Python before, it may take a while, but hey, I get to learn sth. new :-). I never got the word back from Carson, has he developed anything along these lines, but I have to presume he didn't... Anyone interested in joning me, or even earning some money, is still invited to jump on board. My GIS implementation project is well on the way, and it seems there'll even be some money involved :-). Zoran ~joe On Tue, Oct 19, 2010 at 9:55 AM, Andreas Neumann <a.neumann at carto.net>wrote: > Hi Zoran, > > I believe the infrastructure of what you want is already wihtin the > selection and identify tools in QGIS. Isn't this almost implemented in the > current identify tool? > > It sort of is, but not completely. Identify will ID all the features within certain radios (percentage of extent), but it will ID _all_ of the features within this radius. I only need the nearest, no matter how far away... Let us say it is, for simplicity, within current extent. > The current identify tool selects "near" or "close by" features within a > certain tolerance. This tolerance can be set in "Options" --> "Map tools" > "search radius". I believe it currently only effects the identify tool. Do > you want the same tolerance also be used for the click-selection tool? > > Look above. This could be useful, but it is not the functionality I'm currently looking after. > Are you also aware that in QGIS 1.6 there are new selection tools? > > * by click > * by rectangle > * by polygon > * by freehand > * by radius > > Yup, these are great, but they all select _multiple_ features within radius, rectangle, etc. > Maybe this also helps to address your needs? > > Of course you can combine it with previous selections by pressing the ctrl > key. > > BR, --- Zoran Jankovic ZIS-Izrada softvera i savjetovanje / ZIS - Software Development and Consulting http://www.zisis.hr M: 00 385 98 682 902 T: 00 385 44 683 374 A. Senoe 4 44320 Kutina Croatia _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user -- Giuseppe Sucameli -- Giuseppe Sucameli _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user