[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-distance : 2. i think the unity is meter. Could you confirm to me that the unity is meter? I succeed in generating a buffer. But when i measure the value of the buffer with the measurement tool, the value is 15 kms, no 20 kms. Could you throw light for me ? Thanks. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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 lcel...@latitude-geosystems.com 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-distance : 2. i think the unity is meter. Could you confirm to me that the unity is meter? I succeed in generating a buffer. But when i measure the value of the buffer with the measurement tool, the value is 15 kms, no 20 kms. Could you throw light for me ? Thanks. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ 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
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/degrés... My raw linear shp is very long. It is a corridor from Berlin to Beijing. According to you, which coordinate system i should select in order to generate a buffer (20kms)? Thank you. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052521.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Displaying Text from OS Mastermap
Hi Steve, Just a guess, but I'd imagine its the multilineStrings. The loader I use (an FME workbench) converts the text into a line, one correctly oriented and anchored for each point that was in the original dataset. As you can see from my styles and the screenshot - http://hub.qgis.org/wiki/quantum-gis/OS_Styles - QGIS didn't have an issue with this. Someone with better knowledge of QGIS labelling may be able to advise, but the other aspect is to try and load your data so its only a regular line. Jonathan On 9 May 2013 16:14, Steven Campbell s.campb...@poole.gov.uk wrote: Hi ** ** I was wondering if anyone could help. I have my OS Mastermap data stored in a SQL database and whilst I can style the polygons and lines, I am struggling with the text. For some reason, when I use the label option within QGIS, it is displaying the text twice, even though there is only one record/object there to represent the text. For some reason the application I have used to extract my GML into SQL has created multilinestrings for my text, but I don’t know if that explains or not why I am getting duplicate text labels even though there is only one record in the database ** ** Any help would be greatly appreciated. ** ** Thanks ** ** Steve ** ** Steve Campbell GIS Manager Corporate Strategy and Communications Borough of Poole | Civic Centre | Poole BH15 2RU Tel: 01202 633 362 Email: s.campb...@poole.gov.uk Website:www.boroughofpoole.com *Think Green! Please Recycle* ** ** DISCLAIMER: This email and any files transmitted with it may be confidential, legally privileged and protected in law and are intended solely for the use of the individual to whom it is addressed. The copyright in all documentation is the property of the Borough of Poole and this email and any documentation must not be copied or used other than as strictly necessary for the purpose of this email, without prior written consent which may be subject to conditions. Any view or opinions presented are solely those of the author and do not necessarily represent those of the Borough of Poole. The Borough of Poole reserves the right to inspect incoming and outgoing emails. If you have received this email in error please contact the sender by return and confirm that its contents have been destroyed. Telephone enquiries should be directed to the Borough switchboard on 01202 633633. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user -- This transmission is intended for the named addressee(s) only and may contain sensitive or protectively marked material up to RESTRICTED and should be handled accordingly. Unless you are the named addressee (or authorised to receive it for the addressee) you may not copy or use it, or disclose it to anyone else. If you have received this transmission in error please notify the sender immediately. All email traffic sent to or from us, including without limitation all GCSX traffic, may be subject to recording and/or monitoring in accordance with relevant legislation. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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 (EPSG:3857) in order to have meter-based coordinates. But I am not sure it will give you the most accurate resutls (don't know how it distorts the surface). How precise does your buffer need to be? If you work on such a small scale (Berlin - Beijing). I would assume that you don't really care about small distortions, do you? Cheers Stéphane -- Le mot progrès n'aura aucun sens tant qu'il y aura des enfants malheureux -- Albert Einstein A journey does not need reasons. Before long, it proves to be reason enough in itself. One thinks that one is going to make a journey, yet soon it is the journey that makes or unmakes you. -- Nicolas Bouvier Photos de voyages, photos de montagne: http://www.henriod.info On Fri, May 10, 2013 at 12:06 PM, image lcel...@latitude-geosystems.comwrote: 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/degrés... My raw linear shp is very long. It is a corridor from Berlin to Beijing. According to you, which coordinate system i should select in order to generate a buffer (20kms)? Thank you. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052521.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ 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
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 parameters: Segments for approximation (by default) : 5 Buffer distance : 20 Indeed i'm working on such a small scale and i don't care about small distortions. Could you throw light for me? Thanks. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052535.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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 the meters only next to the equator are approximately meters Am 10.05.2013 13:09, schrieb image: 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 parameters: Segments for approximation (by default) : 5 Buffer distance : 20 Indeed i'm working on such a small scale and i don't care about small distortions. Could you throw light for me? Thanks. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Buffer-with-qgis-wgs84-mercator-world-tp5052504p5052535.html Sent from the Quantum GIS - User mailing list archive at Nabble.com. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user -- + FOSSGIS 2013, Die Konferenz für Open Source GIS mit OpenData und OpenStreetMap erstmals in der Schweiz! 12.-14. Juni, HSR, Rapperswil, http://www.fossgis.de/konferenz/2013/ + FOSSGIS e.V. die unabhängige Hilfe bei freier GIS-Software und freien Geodaten http://www.fossgis.de + ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] kriging problems
Hi all, I work with QGIS 1.9 and I noticed a problem with the Sextante-Saga kriging functions. Starting QGIS and without any layers loaded, there aren't problem with the four kriging funcions. But loading some layers (even only one point layer) a python error occurs: Errore durante l'esecuzione di codice Python: Traceback (most recent call last): File /home/matteo/.qgis2/python/plugins/sextante/gui/SextanteToolbox.py, line 138, in executeAlgorithm dlg = ParametersDialog(alg) File /home/matteo/.qgis2/python/plugins/sextante/gui/ParametersDialog.py, line 43, in __init__ self.paramTable = ParametersPanel(self, alg) File /home/matteo/.qgis2/python/plugins/sextante/gui/ParametersPanel.py, line 74, in __init__ self.initGUI() File /home/matteo/.qgis2/python/plugins/sextante/gui/ParametersPanel.py, line 116, in initGUI widget = self.getWidgetFromParameter(param) File /home/matteo/.qgis2/python/plugins/sextante/gui/ParametersPanel.py, line 257, in getWidgetFromParameter item.addItems(self.getFields(layers[0], param.datatype)) File /home/matteo/.qgis2/python/plugins/sextante/gui/ParametersPanel.py, line 325, in getFields for idx, field in fieldMap.iteritems(): AttributeError: 'QgsFields' object has no attribute 'iteritems' Versione Python: 2.7.3 (default, Aug 1 2012, 05:27:35) [GCC 4.6.3] Versione di QGIS: 1.9.0-Master Master, exported Percorso Python: ['/home/matteo/.qgis2/python/plugins/sextante_taudem', '/home/matteo/.qgis2/python/plugins/sextante', '/usr/share/qgis/python', '/home/matteo/.qgis2/python', '/home/matteo/.qgis2/python/plugins', '/usr/share/qgis/python/plugins', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PIL', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/ubuntu-sso-client', '/usr/lib/python2.7/dist-packages/ubuntuone-client', '/usr/lib/python2.7/dist-packages/ubuntuone-control-panel', '/usr/lib/python2.7/dist-packages/ubuntuone-couch', '/usr/lib/python2.7/dist-packages/ubuntuone-installer', '/usr/lib/python2.7/dist-packages/ubuntuone-storage-protocol', '/usr/lib/python2.7/dist-packages/wx-2.8-gtk2-unicode', '/home/matteo/.qgis2/python/plugins/mmqgis/forms', '/usr/share/qgis/python/plugins/fTools/tools'] Ideas? Is it a bug or have these functions a conflict with some path? Cheers, Matteo ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
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, which fits for Europe. HTH, Andre Joost ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Value tool crashes qgis
This is a known problem but needs feedback, please update the following ticket http://hub.qgis.org/issues/7450 On Thu, May 9, 2013 at 9:21 PM, David J. Bakeman dbake...@comcast.netwrote: I've used the value tool in the past but with qgis 1.8 on fedora 18 it crashes qgis on startup every time. ___ 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
