My suggestion would be to create a buffer of 3m around your original points. (vector/geoprocessing/buffer That creates a new vector table. (vector Buffer) Load the new vector table is it isn’t already Then do a spatial query select source features from: new points table Where the feature: within Reference features of : vector buiffer
Open the attributers table of you new points table then click on the invert selection button (yellow triangle with two green arrows in a circle.) Should give you all the points that have moved, assuming that your original points were more than 3 metres apart. Then if you want them as a separate table, just edit/copy Then edit/paste features as Cheers Damien From: qgis-user-boun...@lists.osgeo.org [mailto:qgis-user-boun...@lists.osgeo.org] On Behalf Of Carlos Cerdán Sent: Tuesday, 23 September 2014 3:44 AM To: henrik_f Cc: qgis-user@lists.osgeo.org Subject: Re: [Qgis-user] Finding Points which do not overlay Hi Henrik: If you still don't solve your issue, perhaps you can try this: 1. If you don't have it, Calculate X and Y coords. for your two layers 2. Make a table union, in layer properties 3. Create two new fields for calculate difference of coordinates (Xi - Xj) and (Yi - Yj) 4. Calculate the absolute distance between points in a new field, with the two previous. 5. This last field is your criterion about absolute difference between points. Good luck Carlos Cerdán 2014-09-19 9:35 GMT-05:00 henrik_f <henrik.felt...@gmx.de<mailto:henrik.felt...@gmx.de>>: Hey, So I will get right to the problem I have. I have two different Layers with the same content from different times. Now I want to know which points changed their location and which have been added or deleted so I just wanted to find the points which do not overlay by using Vector -> Geoprocessing Tools -> Difference (I wasnt sure if the one I was looking for was Symetrical Differnce so I tried both) I then realzied that not a single point was overlaying due to the fact that the points that should have the same location were all seperated by about 3 meters. Pictures: In the first picture you see a red point. Out of these kind of points I want to make a new layer. The second picture is a zoomed in version of the area highlighted in the first one. <http://osgeo-org.1560.x6.nabble.com/file/n5162929/Pic1.png> <http://osgeo-org.1560.x6.nabble.com/file/n5162929/Pic2.png> Here is my question: How do I find the points which are not in distance of 3m to each other? I made some attempts with buffers and the difference tool again but non worked. Does anyone have an idea? Greetings Henrik -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Finding-Points-which-do-not-overlay-tp5162929.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org<mailto:Qgis-user@lists.osgeo.org> http://lists.osgeo.org/mailman/listinfo/qgis-user
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