Re: [Qgis-user] Buffer by Attribute Issue

Chris and list It is working for me now. Sorry, when I said lat/long I had meant the points were imported as Lat/Long EPSG:4326 from a text file. But subsequently projected to 3857. Example point in the project CRS ( EPSG:3857) -11923424,5461258 So I think I found the problem. Seems one workflow

Re: [Qgis-user] Buffer by Attribute Issue

Peter and list On Thu, Dec 16, 2021 at 7:08 AM Peter Devanney wrote: > Chris > > The buffer input is a point the lat and long are Doubles. The buffer > distance variable is a Double. Using EPSG 3857 for all. > I just created a point shapefile in EPSG:3857, added a field called "bufferdist", add

Re: [Qgis-user] Buffer by Attribute Issue

Example point in the project CRS ( EPSG:3857) -11923424,5461258 I have had the buffer problem with a GCS like but just usually convert to a UTM to do analysis. I was using a pseudo mercator here because the web maps are in that CRS and don't distort as a base map for a quick view of some data. Buf

Re: [Qgis-user] Buffer by Attribute Issue

The list accepts, I think, 100kb, so you might want to dump your .mp4 somewhere else and post a link. EPSG 3857 is not the most clever CRS to work with, but that depends on your points locations and what you want to do with them. Am 16.12.21 um 16:08 schrieb Peter Devanney: Chris The buffer i

Re: [Qgis-user] Buffer by Attribute Issue

On 12/16/21 16:08, Peter Devanney wrote: Chris The buffer input is a point the lat and long are Doubles. The buffer distance variable is a Double. Using EPSG 3857 for all. So your data is in lat/lon so in degrees? Or in EPSG:3857 units (more or less meters)? Can you show the coordinates of yo

Re: [Qgis-user] Buffer by Attribute Issue

Chris The buffer input is a point the lat and long are Doubles. The buffer distance variable is a Double. Using EPSG 3857 for all. Not sure what the protocol on the list is or if it will accept a small 2 MB .mp4 but I can show what I am doing for workflow if that might help? thanks Chris Peter

Re: [Qgis-user] Buffer by Attribute Issue

Peter and list, On Wed, Dec 15, 2021 at 7:26 AM Peter Devanney wrote: > Hi Folks > > Have a table full of points that I want to buffer by a variable distance. > The distance is an attribute in the input table in km. > > Using Vector>Geoprocessing>Buffer It works fine if I specify a fixed > buffe

Re: [Qgis-user] Buffer by Attribute Issue

Hi, sorry, but can't reproduce your problem (but on Linux Mint QGIS 3.22). Generated 100 random points and added a field "buffer" from $id*10. Everything fine here. Bernd Am 15.12.21 um 16:26 schrieb Peter Devanney: Hi Folks Have a table full of points that I want to buffer by a variable dist

[Qgis-user] Buffer by Attribute Issue

Hi Folks Have a table full of points that I want to buffer by a variable distance. The distance is an attribute in the input table in km. Using Vector>Geoprocessing>Buffer It works fine if I specify a fixed buffer. When I run it with the attribute selected it runs fine but it will not paint the

Re: [Qgis-user] buffer around random points

Hi, You can use a vector layer as suggested or use a raster layer with a specific value for land or water. You can then use something like the point sampling tool plugin (a plugin that you must install and activate) to retrieve the value of the point on the raster of vector layer. Make sure

Re: [Qgis-user] buffer around random points

Hi Milena, There's an algorithm "Random Points in Polygons" that will only return points within the polygons of a layer. So you need a vector layer for land for the area you are interested in. Hope this helps, Raymond On 14-04-2021 08:36, Milena Muehler wrote: Dear community! I’m new to QG

[Qgis-user] buffer around random points

Dear community! I’m new to QGIS and hope you can follow my process and my question. Would be more than happy to get your help! So I have a raster layer with a cumulative value for each raster giving information about land modification (in 2016) I have another vector layer with points provid

Re: [Qgis-user] Buffer Algorithm (Buffer distance of output polygon is not equal to the Distance parameter)

That's odd. I redid the entire thing just now (restarted QGIS, made scratch point layer, created a 100m buffer) and the values I get are now correct. Even the area computations were off in the first one but after redoing the process, everything looks good. point-buffer2.png

Re: [Qgis-user] Buffer Algorithm (Buffer distance of output polygon is not equal to the Distance parameter)

Hi, There might be more information in the *Info* drop-down menu. Expand it, please. Harrissou Le jeu. 27 sept. 2018 à 16:55, Ben Hur Pintor a écrit : > Hi everyone. > > I apologize if this has been asked before but I would just like to clarify > if this is how the buffer algorithm in QGIS shou

[Qgis-user] Buffer Algorithm (Buffer distance of output polygon is not equal to the Distance parameter)

Hi everyone. I apologize if this has been asked before but I would just like to clarify if this is how the buffer algorithm in QGIS should function. *Issue:* The actual distance from the input layer to the buffer polygon created by the Buffer processing tool (and v.buffer) is not equal (only arou

Re: [Qgis-user] Buffer distance doubt

Yes. Probably you're working with geographic coordinates (longlat) and you're getting a buffer of 1 grade, it makes sense depending on your latitude. 2014-03-27 3:32 GMT-06:00 Zoltan Szecsei : > errr.. never worked with QGIS buffers, and you haven't given much info, > but: > > Is your coord sys

Re: [Qgis-user] Buffer distance doubt

errr.. never worked with QGIS buffers, and you haven't given much info, but: Is your coord system LatLong? Depending on your latitude, 1 degree can be about 100km HTH, Zoltan On 2014/03/27 11:23, Luis Miguel Royo Pérez wrote: Hi everyone, I've got a doubt about buffer in the field "Distance".

[Qgis-user] Buffer distance doubt

Hi everyone, I've got a doubt about buffer in the field "Distance"... why are multiple of 100km? I mean, if I insert *1*, the buffer is about *100*km, and so on. Anyone can resolve my doubt? Thank you!!! ___ Qgis-user mailing list Qgis-user@list

Re: [Qgis-user] buffer

It would have been better, if QGIS had taken buffer distances using 'Ellipsoid', as it does in the case of 'Measure tool'. Regards Harish ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] buffer

_ From: qgis-user-boun...@lists.osgeo.org [qgis-user-boun...@lists.osgeo.org] on behalf of daniel pinto [daniel.ar.pi...@gmail.com] Sent: 23 November 2013 21:38 To: qgis-user@lists.osgeo.org Subject: [Qgis-user] buffer hello!! i´m trying to create a 50 meter buffer around two points, 50 meters

Re: [Qgis-user] buffer

Hi Daniel, Am 23.11.2013, 21:38 Uhr, schrieb daniel pinto : hello!! i´m trying to create a 50 meter buffer around two points, 50 meters each in a shape file and the created buffer is the size of portugal... i think the units are well configured but can´t seem to figure Can you share the dat

[Qgis-user] buffer

hello!! i´m trying to create a 50 meter buffer around two points, 50 meters each in a shape file and the created buffer is the size of portugal... i think the units are well configured but can´t seem to figure out how to get it right i'm using dufor 2.0.1 any help is more then welcome thanks

Re: [Qgis-user] Buffer segments to approximate

Dear Andreas, Horst Thanks a lot for your answers, it's perfect. Maybe it could be interesting to insert this kind of things in the documentation ? Ludovic Le 19/11/2013 17:29, Horst Düster a écrit : -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Ludovic The number of segments depends on t

Re: [Qgis-user] Buffer segments to approximate

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Ludovic The number of segments depends on the exactness of the results you expect. If you create a circle buffer around a point with radius of 1 the area of the circle will running against PI with increasing number of segments. Now you have to dec

Re: [Qgis-user] Buffer segments to approximate

Hi, Buffers for points are round. There are also round corners for line/polygon buffers, depending on the linecap styles and line join styles. QGIS and simple features can only display straight lines. The number of the segements to approximate means the higher the number, the more vertices yo

[Qgis-user] Buffer segments to approximate

Hi all Is there anyone could tell me what is "segments to approximate" in the buffer tool ? I know that if I increase this value, there's more nodes on my buffer but I don't know what is it exactly and how we can choose this value. Thanks Regards Ludovic__

[Qgis-user] buffer

Need to generate a buffer in relation to a shore line, but only in one direction, and not for the right and left. Can anyone help? How do? Thanks Dario___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-use

Re: [Qgis-user] buffer

See if this helps: http://gis.stackexchange.com/questions/32973/how-to-buffer-a-line-with-different-distances-for-left-right-sides Best regards, Alexandre Neto On Tue, Sep 3, 2013 at 4:43 PM, Dario wrote: > Need to generate a buffer in relation to a shore line, but only in one > direction, a

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

Am 10.05.2013 13:48, schrieb image: Hi Marco. Thank you. But my data is a big very long corridor from Berlin to Beijing...;-) If your route comes close to the north pole, EPSG:3408 or EPSG:3575 or EPSG:3576 would fit. These are Lambert Azimutal Equal Aerea projection. Or take EPSG:3035, w

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

How about a Global UTM WGS 84 projection? -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052619.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ Qgis-u

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

Hi Marco. Thank you. But my data is a big very long corridor from Berlin to Beijing...;-) -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052546.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. __

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

HI image, the "meters" in Pseudo Mecator or Google Mercator are not exact meters in reality. Use a better metric projected CRS available for your region of work (where is your data located). You could use the UTM (e.g. 32632 if in Germany) to get far better results. Marco P.S. in Google Mercator

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

Thank you. I just tried a test to generate a buffer 20 meters from my linear shp(with pseudo mercator). It works. But when i measure, the buffer is not to 20 meters but 12/14 meters. Could you just make a quick test on your side please? Via the interface called Buffer i have entered those par

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

Hi I assume there is a misundersanding. I guess Jo assumed that your data is stored in a PostGIS database, which is why he advised to cast the coordinates as GEOGRAPHY. As you seem to be working with shapefiles, this actually doesn't concern you. I would project my data into pseudo-mercator (EPS

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

Hello, Thank you for your reply. But sorry i do not really understand. Could you make explicit please? What do you understand by 'geography'? I just make a new test with world mercator & wgs84 also and the result of the buffers are always big circle . So i suppose that the unity is radians/deg

Re: [Qgis-user] Buffer with qgis : wgs84/mercator world?

If you store in a geography the unit is meters. If you store WGS84 in a geometry it's radians/degrees. Try casting to ::GEOGRAPHY. Jo 2013/5/10 image > Hello, > > i would like generate a buffer (20kms) around my shapefile (line). > > In a 1st time, i tied to do that with wgs84 parameters (for t

[Qgis-user] Buffer with qgis : wgs84/mercator world?

Hello, i would like generate a buffer (20kms) around my shapefile (line). In a 1st time, i tied to do that with wgs84 parameters (for the layer & project). But the result was a big circle. In 2 2nd time, i converted my raw shapefile into wgs 84 mercator world. I entered this value for buffer-d

[Qgis-user] buffer overlaps

Dear Users, 1) I need to count the buffer overlaps using vector. Can someone tell me how I can do this in QGIS Pl. 2) Again, I need to overlay (union) multiple vector layers in one shot. Is there a plug in or a method to do this. Pls let me know. Thank you and with best regards, *Sohan* _

Re: [Qgis-user] buffer crashes Xorg?

Hi Paolo Please post a sample. Though it could be a geos issue. Which version are you using? Regards, Marco Am Donnerstag, 24. September 2009 14.51:51 schrieben Sie: > Hi all. > Calculating a buffer on a moderately complex polygon layer eats up a lot of > resources, until the entire Xorg sessio

[Qgis-user] buffer crashes Xorg?

Hi all. Calculating a buffer on a moderately complex polygon layer eats up a lot of resources, until the entire Xorg session crashes: does anybody have the same problem? If so, we can fill a ticket and attach a sample file. Thanks. -- Paolo Cavallini: http://www.faunalia.it/pc ___

[Qgis-user] buffer function

Hi! I never get the buffer function working - what ever version I use (0.7, 0.8, 0.11). The problem is that the tables are not created in my postgres/postgis database, although there is no error message. The connection is ok. If I do it manually using the psql-client it is working. What may be