Re: [Qgis-user] Area calculation tools
Hi Stephane, if you calculate areas (or length) with the "Add geometry Columns"-Tool, the results depend on the settings you can make under "Calculate using". Here you have the options Layer CRS, Project CRS or Ellipsoid. Ellipsoid is calculating with the curvature of the earth (so far I know) and the others depending on the CRS' of the layer or the project (when 'on the fly' CRS transformation is enabled). If you are using $area in the field calculator it depends if 'on the fly' CRS transformation is enabled or not. If it is not enabled it calculates with the layer CRS, if it is enabled it should calculate with the project CRS. These are my testing experiences so I'm not 100% sure, but maybe there is someone who has more informations about this topic. ralf -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Area-calculation-tools-tp5173073p5173091.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] Switch on only 1 layer of a group
Many thx Salvatore, I try it. 2014-11-14 20:10 GMT+01:00 Salvatore Larosa : > Hi Andrea, > > On Fri, Nov 14, 2014 at 9:42 AM, Salvatore Larosa wrote: >> No idea on how to do such an action from python but I think that >> should be handy to do from C++ to have it available in group context >> menu, something like a checkbox "Alternate layers". maybe could you >> open a feature request? > > ok, for a workaround python is the road to go, you can use the > snippets to the link [0] like a python macro into your project. > Only change the group name (the groupName variable) which you want to > apply to such feature. > > Best Regards, > -SL > > [0] - http://codepad.org/BmYxVHgy > > -- > Salvatore Larosa > linkedIn: http://linkedin.com/in/larosasalvatore > twitter: @lrssvt > skype: s.larosa > IRC: lrssvt on freenode -- - Andrea Peri . . . . . . . . . qwerty àèìòù - ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Switch on only 1 layer of a group
Hi Andrea, On Fri, Nov 14, 2014 at 9:42 AM, Salvatore Larosa wrote: > No idea on how to do such an action from python but I think that > should be handy to do from C++ to have it available in group context > menu, something like a checkbox "Alternate layers". maybe could you > open a feature request? ok, for a workaround python is the road to go, you can use the snippets to the link [0] like a python macro into your project. Only change the group name (the groupName variable) which you want to apply to such feature. Best Regards, -SL [0] - http://codepad.org/BmYxVHgy -- Salvatore Larosa linkedIn: http://linkedin.com/in/larosasalvatore twitter: @lrssvt skype: s.larosa IRC: lrssvt on freenode ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Area calculation tools
Hello. I've noticed that there are in the feature area calculated by Vector > Geometry Tools > Export/Add Geometry Columns" vs. using $area in the field calculator. For the same polygon I got 151 482 883.964722 m2 for the first one and 152 548 334.467394 m2 for the second. This is a 106ha difference for a 15k ha area. Does someone know which one of the tools is more precise, and why ? Thanks Stephane ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] The WMS Legend lost the scale in getlegendgraphics.
Hi, I notice the WMS legend in the tree don't use the SCALE parameter. so when calling a wms appeare all the styles for every scale interval. :( I'm using the qgis 2.6. Perhaps there is a special property to activate the scale parameter ? Thx, -- - Andrea Peri . . . . . . . . . qwerty àèìòù - ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Stacking Landsat Bands
Thanks for the replies. Lots of options, useful to know. @Andreas - My issue was that my bands were separate images, I don't believe I can visualise them in a RGB-ish manner without first stacking into a single image. Cheers, Jonathan -Original Message- From: qgis-user-boun...@lists.osgeo.org [mailto:qgis-user-boun...@lists.osgeo.org] On Behalf Of Andreas Neumann Sent: Thursday, November 13, 2014 3:25 PM To: qgis-user@lists.osgeo.org Subject: Re: [Qgis-user] Stacking Landsat Bands Hi, If it is just for display you can display the landsat image in QGIS right away. You can freely assign selected bands to rgb channels in the "Style" tab of QGIS. So no need to recalculate images ... Andreas Am 2014-11-13 16:12, schrieb Eric Goddard: > Hi Jonathan, Did you try the GDAL merge tool (Raster -> Miscellaneous > -> Merge)? If you check the layer stack box it will create a multiband > image with any number of input files. > > Eric > > On Thu, Nov 13, 2014 at 8:31 AM, Carl wrote: >> Jonathan >> I'm not familiar with the Orfeo tool but I use the SAGA Rgb Composite >> tool under SAGA\Grid-Visualization\ to stack Landsat scenes. It >> limits you to three bands which is a bummer, but works well. The tool >> output is rescaled to 8-bit, so you shouldn't use the stacked imagery >> for change analysis later, but it’s great for visualization. >> The GRASS Raster tool r.composite will also stack, but the SAGA tool >> seems to handle Landsat 7 SLC-off data gaps better. >> I’m new to QGIS, so some of the above might be wrong... >> Carl >> >> >> >> >> -- >> View this message in context: >> http://osgeo-org.1560.x6.nabble.com/Stacking-Landsat-Bands-tp5172804p >> 5172838.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 ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user This message has been scanned for viruses by MailControl - www.mailcontrol.com Click https://www.mailcontrol.com/sr/jgWlSnkjgqHGX2PQPOmvUoRq5N+0kMbNZPKdu!+f58dejC57TnCbJIsDGAD0hjxQcKOXBjNJKDyn9BVBzDB66w== to report this email as spam. HR Wallingford and its subsidiaries uses faxes and emails for confidential and legally privileged business communications. They do not of themselves create legal commitments. Disclosure to parties other than addressees requires our specific consent. We are not liable for unauthorised disclosures nor reliance upon them. If you have received this message in error please advise us immediately and destroy all copies of it. HR Wallingford Limited Howbery Park, Wallingford, Oxfordshire, OX10 8BA, United Kingdom Registered in England No. 02562099 ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Switch on only 1 layer of a group
Hi, On Fri, Nov 14, 2014 at 9:10 AM, aperi2007 wrote: > Hi Salvatore, > > thx for hint. > It is a very interesting feature. > I dont know it. > > But unfortunately it dont seem to be what I need. ok, my immagination was wrong :) > > My need is showing the the user all the layer of a group. > > they are all wms layer of kind OFC ortophoto, and each of them cover all the > land. > So If perfectly unuseful for the user turn on more than one layer at same > time. > So the need is avoid that the user turn off more than one of them. > > This is a standard feature in some webgis framework. > And it will be useful aso in a qgis project to avoid that the user could > turn on some layers that are not > useful to see both at the same time. > And if turn on more than one at the same time it see only the upper (the > other are covered) but the > time to show the map and the network traffic is for all of them. So you want to alternate layers that cover each other? That is a cool feature, but it is not possible to do right now. > > AFAIK this feature dont seem to be available so I'm evaluating if is > possible to support it with a few of python code in an action. No idea on how to do such an action from python but I think that should be handy to do from C++ to have it available in group context menu, something like a checkbox "Alternate layers". maybe could you open a feature request? > > A. > > > Il 14/11/2014 08:53, Salvatore Larosa ha scritto: > >> Hi, >> >> On Fri, Nov 14, 2014 at 7:33 AM, Andrea Peri wrote: >>> >>> Hi, I need to set a qgis project to turn on only 1 layer from a group. >>> When >>> a layer is turn on the others should be turn off. >>> I guess this is not possibile from group properties, but is possibile to >>> set >>> an action to turn off every layer in a group other than the actual layer >>> turn on ? >> >> I guess what you are looking for is adding a "Preset" in legend tree. >> This is a new feature found in 2.6. >> Turn off all layers and activate the only layer which you want display >> then add a Preset (from eye icon). >> >> Best Regards, >> -SL >> >> > -- Salvatore Larosa linkedIn: http://linkedin.com/in/larosasalvatore twitter: @lrssvt skype: s.larosa IRC: lrssvt on freenode ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Switch on only 1 layer of a group
Hi Salvatore, thx for hint. It is a very interesting feature. I dont know it. But unfortunately it dont seem to be what I need. My need is showing the the user all the layer of a group. they are all wms layer of kind OFC ortophoto, and each of them cover all the land. So If perfectly unuseful for the user turn on more than one layer at same time. So the need is avoid that the user turn off more than one of them. This is a standard feature in some webgis framework. And it will be useful aso in a qgis project to avoid that the user could turn on some layers that are not useful to see both at the same time. And if turn on more than one at the same time it see only the upper (the other are covered) but the time to show the map and the network traffic is for all of them. AFAIK this feature dont seem to be available so I'm evaluating if is possible to support it with a few of python code in an action. A. Il 14/11/2014 08:53, Salvatore Larosa ha scritto: Hi, On Fri, Nov 14, 2014 at 7:33 AM, Andrea Peri wrote: Hi, I need to set a qgis project to turn on only 1 layer from a group. When a layer is turn on the others should be turn off. I guess this is not possibile from group properties, but is possibile to set an action to turn off every layer in a group other than the actual layer turn on ? I guess what you are looking for is adding a "Preset" in legend tree. This is a new feature found in 2.6. Turn off all layers and activate the only layer which you want display then add a Preset (from eye icon). Best Regards, -SL ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
