Re: [QGIS-Developer] Updating a layer's datasource in python
Hi Olivier,
I have been playing with this and I think you should use the source on the
layer and not on the data provider.
Here is some code (which also modifies the style of the layer)
https://github.com/QGEP/customizer/blob/master/customizer.py#L129-L141
I was doing a layer.reload() after changing the source.
Hope that helps,
Denis
Le mar. 25 sept. 2018 à 19:02, Olivier Dalang a
écrit :
> Dear List,
>
> As simple as it sounds, I'm struggling with changing the datasource of
> layers with python :
>
> layer1 = QgsVectorLayer('/path/to/a.shp')
> QgsProject.instance().addMapLayer(layer1)
> layer1.dataProvider().setDataSourceUri('/path/to/b.shp')
>
> The layer successfully changes on map redraw. However layer1.source()
> stays to the initial layer, so that the change does not persist across
> saves (save and reload, and you get a.shp again).
>
> The exact same code with a geopackage doesn't work at all (no changes on
> map redraw).
>
> layer1 = QgsVectorLayer('/path/to/db.gpkg|layer=a')
> QgsProject.instance().addMapLayer(layer1)
> layer1.dataProvider().setDataSourceUri ('/path/to/db.gpkg|layer=b')
>
> There is also an entry in the pyqgis cookbook (here
> ,
> scroll down) for QgsVectorLayer. The layer1.source() is correctly updated,
> but again, it works with shapefiles, but not geopackages. And this is for
> vectors only.
>
> layer1.setDataSource('/path/to/b.shp', "b", "ogr")
>
> Am I hitting a bug ? Or did I get confused somewhere ?
>
> As I feel this is a fairly common need, I'd be very grateful if someone
> could help me figure out the recommended way to achieve this, for both
> vectors or rasters. I'll update the pyqgis cookbook in return :-)
>
> Note that there are workarounds (like replacing with a new layer and
> copying styles over or writing directly to the .qgs file, but they are not
> straightforward and have limitations).
>
> Thanks !!
>
> Olivier
>
>
>
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--
Denis Rouzaud
de...@opengis.ch
+41 76 370 21 22
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Re: [QGIS-Developer] Updating a layer's datasource in python
On Wed, 26 Sep 2018 at 09:02, Olivier Dalang wrote:
>
> Dear List,
>
> As simple as it sounds, I'm struggling with changing the datasource of layers
> with python :
>
> layer1 = QgsVectorLayer('/path/to/a.shp')
> QgsProject.instance().addMapLayer(layer1)
> layer1.dataProvider().setDataSourceUri('/path/to/b.shp')
This code won't work correctly -- you shouldn't be changing the data
source of the layer's provider, but rather set the layer's data source
and let it handle the required changes to the provider.
> There is also an entry in the pyqgis cookbook (here, scroll down) for
> QgsVectorLayer. The layer1.source() is correctly updated, but again, it works
> with shapefiles, but not geopackages. And this is for vectors only.
This should work for geopackage (as well as shp). Can you share your code?
And yes, there's unfortunately no equivalent for rasters yet.
Nyall
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[QGIS-Developer] Updating a layer's datasource in python
Dear List,
As simple as it sounds, I'm struggling with changing the datasource of
layers with python :
layer1 = QgsVectorLayer('/path/to/a.shp')
QgsProject.instance().addMapLayer(layer1)
layer1.dataProvider().setDataSourceUri('/path/to/b.shp')
The layer successfully changes on map redraw. However layer1.source() stays
to the initial layer, so that the change does not persist across saves
(save and reload, and you get a.shp again).
The exact same code with a geopackage doesn't work at all (no changes on
map redraw).
layer1 = QgsVectorLayer('/path/to/db.gpkg|layer=a')
QgsProject.instance().addMapLayer(layer1)
layer1.dataProvider().setDataSourceUri ('/path/to/db.gpkg|layer=b')
There is also an entry in the pyqgis cookbook (here
,
scroll down) for QgsVectorLayer. The layer1.source() is correctly updated,
but again, it works with shapefiles, but not geopackages. And this is for
vectors only.
layer1.setDataSource('/path/to/b.shp', "b", "ogr")
Am I hitting a bug ? Or did I get confused somewhere ?
As I feel this is a fairly common need, I'd be very grateful if someone
could help me figure out the recommended way to achieve this, for both
vectors or rasters. I'll update the pyqgis cookbook in return :-)
Note that there are workarounds (like replacing with a new layer and
copying styles over or writing directly to the .qgs file, but they are not
straightforward and have limitations).
Thanks !!
Olivier
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Re: [QGIS-Developer] open atlas layout, using python
On Tue, 25 Sep 2018 at 22:36, Raymond Nijssen wrote: > > 1. Can I open a layout window with a python command? designer = iface.openLayoutDesigner( layout ) > 2. Can I turn on "atlas preview" with a python command? You'd have to do some fragile code to do this. Basically: - get designer window from designer.view()'s parent window - find the mActionAtlasPreview child action in the window - manually toggle it on This should work, but isn't stable API - so is likely to break ;) A better approach is to (quickly, before 3.4 final!) file a PR exposing the toggle atlas preview behavior to QgsLayoutDesignerInterface. Then you'll be able to just do: designer = iface.openLayoutDesigner( layout ) designer.toggleAtlasPreview( True ) Nyall Hope anyone knows! > > Kind regards, > Raymond > > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-psc] Fwd: Documentation writing
Hi Harrissou, thanks for reporting your ideas, probably nobody knows better than you "black areas" of the docs. What do other docs people think? I don't want to put too much wood in the fire, but maybe if we all agree, we can think to add some priority labels depending on the lack of documented (interested) features. QGIS doc repo already has a lot (too much?!) labels, but maybe having a kind of hierarchy could help. Thanks Matteo ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
>[...] >Caris LOTS: 14.737 km^2 >ArcMap: 14.727,446 km^2 >MapInfo:14.727,352 km^2 >GeoMedia: 14.726,443 km^2 >Planimeter: 14.722,522 km^2 >QGIS 3.2: 14.652,181 km^2 >QGIS 2.8: 14.652,181 km^2 >[...] >My suspicion is that the geodesic algorithm used by QGIS (and apparently GRASS) is to blame here. a quick check in GRASS 7.7.svn shows :-) |m2|km2| |14718097678,673|14.718,097679| - best regards Helmut -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-Developer-f4099106.html ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
[QGIS-Developer] Exporting from QGIS to CAD format - is it possible to offer DWG export
Hi, The CAD import and export functions for QGIS 3x are already extremely impressive and in several ways exceed the import/export capability of ArcGIS desktop 10.5/6. As mentioned in a previous post the only function that the QGIS import can't handle yet is when the CAD file (dwg or dxf) is not georeferenced beforehand. For that scenario I regrettably have to go back to ArcGIS desktop. My question pertains to the export. Is there a proprietary licensing reason that QGIS cannot export directly to *.dwg file format rather than only to the dxf format? I have a colleague that regularly espouses the view that QGIS is not up to par when it comes to handling CAD files, as compared to ArcGIS desktop, simply because of Q's inability to export directly to a dwg file format. Can this capability be added? Regards Rob ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
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Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
Calvin, I am quite sure that Charles Karney holds an undisputed claim of the Most Accurate Geodesic Algorithm™. At least I haven’t come across any papers offering better accuracy. Google Earths figure of 14.672 km^2 is very similar to MapInfos spherical area calculation of 14.670 km^2, so for now I think we can assume that Google’s Earth is not subject to either rotation nor gravity :-) Regarding including the gravity (geoid) models in GeographicLib I must admit that that is outside my knowledge of the library. If the library can calculate geodesics on the geoid that would be even more accurate, yes. Although you are at the mercy of the accuracy of the geoid models. For my particular application I wouldn’t use one since the global models mention in the docs you link to are not that well-fitting in this area. In theory I could produce a grid from a better geoid model. While an interesting problem to handle I think it is taking it just a step too far. /Kristian Fra: C Hamilton Sendt: 25. september 2018 16:27 Til: Kristian Evers Cc: Nyall Dawson ; qgis-developer Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 Kristian, Thanks for those calculations. Before this discussion I was contemplating doing a line and polygon measurement tool for Shape Tools by clicking on an existing shape and using geographiclib calculate the measurements, but if it is possible to replace the existing QGIS measuring functions and Vincinty with geographiclib, then I will hold off. Shape Tools uses geographiclib for all its calculations and I am pleased with it. In the last release I included a function to measure all geometry on a layer. I don't know who has the most accurate algorithm. I just checked Google Earth and it measures your polygon at 14,672 km^2. I'm guessing Google Earth is not as accurate as some of those other applications. As far as I know geographiclib has the most accurate ellipsoid calculations. The only thing better would be to include elevation. I'm not an expert in this area, but would the gravity models provide more accuracy? https://geographiclib.sourceforge.io/html/gravity.html#gravityinst Calvin On Tue, Sep 25, 2018 at 9:31 AM, Kristian Evers mailto:kr...@sdfe.dk>> wrote: Right, here are the calculated areas as returned by a number of different GIS applications and the planimeter app of GeographicLib for reference: Caris LOTS: 14.737 km^2 ArcMap: 14.727,446 km^2 MapInfo:14.727,352 km^2 GeoMedia: 14.726,443 km^2 Planimeter: 14.722,522 km^2 QGIS 3.2: 14.652,181 km^2 QGIS 2.8: 14.652,181 km^2 The polygon that I have used to get the numbers above can be found here: https://gist.github.com/kbevers/207b5bcb9be20e7554abe5f56742ec2c I am quite confident that GeographicLib delivers the most accurate result (if you have doubts, this reference [0] should convince you). As can be seen from the table above all but QGIS come fairly close. I expect some variation in the results as these are numerical approximations, although I think QGIS is too far of the mark. My suspicion is that the geodesic algorithm used by QGIS (and apparently GRASS) is to blame here. /Kristian [0] https://arxiv.org/pdf/1102.1215.pdf -Oprindelig meddelelse- Fra: QGIS-Developer mailto:qgis-developer-boun...@lists.osgeo.org>> På vegne af Kristian Evers Sendt: 25. september 2018 09:15 Til: Nyall Dawson mailto:nyall.daw...@gmail.com>> Cc: qgis-developer mailto:qgis-developer@lists.osgeo.org>> Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 It's not a small area, that's why I have been nitpicking ellipsoid area calculation algorithms! I did end up doing the calculations with geographiblib to get a reference to judge various other calculations by. It's a pain in the butt to extract the data from a polygon shapefile (or whatever) and format it to suit the planimeter app of geographiclib. It would be so much cooler if I could get the same results by clicking info on a polygon in QGIS :-) /Kristian -Oprindelig meddelelse- Fra: Nyall Dawson mailto:nyall.daw...@gmail.com>> Sendt: 25. september 2018 09:07 Til: Kristian Evers mailto:kr...@sdfe.dk>> Cc: Paolo Cavallini mailto:cavall...@faunalia.it>>; qgis-developer mailto:qgis-developer@lists.osgeo.org>> Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 On Tue, 25 Sep 2018 at 16:59, Kristian Evers mailto:kr...@sdfe.dk>> wrote: > > Hi Paolo, > > I have some rought notes that I can try to polish up a bit and share here. > I'll see if I can find the time for that today. I didn't get to the bottom of > the problem but I am leaning towards the issue being that QGIS uses an > inferior algorithm to determine geodesics. Unfortunately I couldn't find out > from either the source code or the documentation which algorithm is used. > As far as I remember it differs from the otherwise popular algorithm by > Vincenty. That may be because a different algorithm is
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
Kristian, Thanks for those calculations. Before this discussion I was contemplating doing a line and polygon measurement tool for Shape Tools by clicking on an existing shape and using geographiclib calculate the measurements, but if it is possible to replace the existing QGIS measuring functions and Vincinty with geographiclib, then I will hold off. Shape Tools uses geographiclib for all its calculations and I am pleased with it. In the last release I included a function to measure all geometry on a layer. I don't know who has the most accurate algorithm. I just checked Google Earth and it measures your polygon at 14,672 km^2. I'm guessing Google Earth is not as accurate as some of those other applications. As far as I know geographiclib has the most accurate ellipsoid calculations. The only thing better would be to include elevation. I'm not an expert in this area, but would the gravity models provide more accuracy? https://geographiclib.sourceforge.io/html/gravity.html#gravityinst Calvin On Tue, Sep 25, 2018 at 9:31 AM, Kristian Evers wrote: > Right, here are the calculated areas as returned by a number of different > GIS applications and the planimeter app of GeographicLib for reference: > > Caris LOTS: 14.737 km^2 > ArcMap: 14.727,446 km^2 > MapInfo:14.727,352 km^2 > GeoMedia: 14.726,443 km^2 > Planimeter: 14.722,522 km^2 > QGIS 3.2: 14.652,181 km^2 > QGIS 2.8: 14.652,181 km^2 > > The polygon that I have used to get the numbers above can be found here: > https://gist.github.com/kbevers/207b5bcb9be20e7554abe5f56742ec2c > > I am quite confident that GeographicLib delivers the most accurate result > (if you have doubts, this reference [0] should convince you). As can be > seen from the table above all but QGIS come fairly close. I expect some > variation in the results as these are numerical approximations, although I > think QGIS is too far of the mark. My suspicion is that the geodesic > algorithm used by QGIS (and apparently GRASS) is to blame here. > > /Kristian > > [0] https://arxiv.org/pdf/1102.1215.pdf > > -Oprindelig meddelelse- > Fra: QGIS-Developer På vegne af > Kristian Evers > Sendt: 25. september 2018 09:15 > Til: Nyall Dawson > Cc: qgis-developer > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > It's not a small area, that's why I have been nitpicking ellipsoid area > calculation > algorithms! > I did end up doing the calculations with geographiblib to get a reference > to judge > various other calculations by. It's a pain in the butt to extract the data > from a > polygon shapefile (or whatever) and format it to suit the planimeter app of > geographiclib. It would be so much cooler if I could get the same results > by > clicking info on a polygon in QGIS :-) > > /Kristian > > > -Oprindelig meddelelse- > Fra: Nyall Dawson > Sendt: 25. september 2018 09:07 > Til: Kristian Evers > Cc: Paolo Cavallini ; qgis-developer < > qgis-developer@lists.osgeo.org> > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > On Tue, 25 Sep 2018 at 16:59, Kristian Evers wrote: > > > > Hi Paolo, > > > > I have some rought notes that I can try to polish up a bit and share > here. > > I'll see if I can find the time for that today. I didn't get to the > bottom of > > the problem but I am leaning towards the issue being that QGIS uses an > > inferior algorithm to determine geodesics. Unfortunately I couldn't find > out > > from either the source code or the documentation which algorithm is used. > > As far as I remember it differs from the otherwise popular algorithm by > > Vincenty. That may be because a different algorithm is used or the > > Implementation is wrong. > > > > I'll get back with a better write-up later and some test data and > results. > > We use a direct port from GRASS: > > https://github.com/qgis/QGIS/blob/master/src/core/qgsdistancearea.cpp#L690 > > vs GRASS upstream: > > https://trac.osgeo.org/grass/browser/grass/trunk/lib/gis/ > area_poly1.c?rev=71260 > > It's not very stable for very small areas -- better to use cartesian > calculations there. Or bring in geographiclib and punt the > responsibility elsewhere ;) > > Nyall > > > > > > > /Kristian > > > > -Oprindelig meddelelse- > > Fra: QGIS-Developer På vegne > af Paolo Cavallini > > Sendt: 25. september 2018 08:23 > > Til: qgis-developer@lists.osgeo.org > > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > > > Hi Kristian, > > > > > > Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > > > > > > > On a related note, I have been meaning to raise a similar issue based > > > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > > > A colleague of mine came across some differences between QGIS and > > > CARIS LOTS while doing area calculations in relation to a border > > > dispute at sea. After that I tested several popular closed source GIS > > > apps and they all performed better than QGIS.
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
Right, here are the calculated areas as returned by a number of different GIS applications and the planimeter app of GeographicLib for reference: Caris LOTS: 14.737 km^2 ArcMap: 14.727,446 km^2 MapInfo:14.727,352 km^2 GeoMedia: 14.726,443 km^2 Planimeter: 14.722,522 km^2 QGIS 3.2: 14.652,181 km^2 QGIS 2.8: 14.652,181 km^2 The polygon that I have used to get the numbers above can be found here: https://gist.github.com/kbevers/207b5bcb9be20e7554abe5f56742ec2c I am quite confident that GeographicLib delivers the most accurate result (if you have doubts, this reference [0] should convince you). As can be seen from the table above all but QGIS come fairly close. I expect some variation in the results as these are numerical approximations, although I think QGIS is too far of the mark. My suspicion is that the geodesic algorithm used by QGIS (and apparently GRASS) is to blame here. /Kristian [0] https://arxiv.org/pdf/1102.1215.pdf -Oprindelig meddelelse- Fra: QGIS-Developer På vegne af Kristian Evers Sendt: 25. september 2018 09:15 Til: Nyall Dawson Cc: qgis-developer Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 It's not a small area, that's why I have been nitpicking ellipsoid area calculation algorithms! I did end up doing the calculations with geographiblib to get a reference to judge various other calculations by. It's a pain in the butt to extract the data from a polygon shapefile (or whatever) and format it to suit the planimeter app of geographiclib. It would be so much cooler if I could get the same results by clicking info on a polygon in QGIS :-) /Kristian -Oprindelig meddelelse- Fra: Nyall Dawson Sendt: 25. september 2018 09:07 Til: Kristian Evers Cc: Paolo Cavallini ; qgis-developer Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 On Tue, 25 Sep 2018 at 16:59, Kristian Evers wrote: > > Hi Paolo, > > I have some rought notes that I can try to polish up a bit and share here. > I'll see if I can find the time for that today. I didn't get to the bottom of > the problem but I am leaning towards the issue being that QGIS uses an > inferior algorithm to determine geodesics. Unfortunately I couldn't find out > from either the source code or the documentation which algorithm is used. > As far as I remember it differs from the otherwise popular algorithm by > Vincenty. That may be because a different algorithm is used or the > Implementation is wrong. > > I'll get back with a better write-up later and some test data and results. We use a direct port from GRASS: https://github.com/qgis/QGIS/blob/master/src/core/qgsdistancearea.cpp#L690 vs GRASS upstream: https://trac.osgeo.org/grass/browser/grass/trunk/lib/gis/area_poly1.c?rev=71260 It's not very stable for very small areas -- better to use cartesian calculations there. Or bring in geographiclib and punt the responsibility elsewhere ;) Nyall > > /Kristian > > -Oprindelig meddelelse- > Fra: QGIS-Developer På vegne af > Paolo Cavallini > Sendt: 25. september 2018 08:23 > Til: qgis-developer@lists.osgeo.org > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > Hi Kristian, > > > Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > > > > On a related note, I have been meaning to raise a similar issue based > > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > > A colleague of mine came across some differences between QGIS and > > CARIS LOTS while doing area calculations in relation to a border > > dispute at sea. After that I tested several popular closed source GIS > > apps and they all performed better than QGIS. > this is worth exploring in detail. could you please be more specific? do > you have a test case? could you share the results, or give us a way to > replicate them? > Thanks. > > -- > Paolo Cavallini - www.faunalia.eu > QGIS.ORG Chair: > http://planet.qgis.org/planet/user/28/tag/qgis%20board/ > > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
[QGIS-Developer] open atlas layout, using python
1. Can I open a layout window with a python command? 2. Can I turn on "atlas preview" with a python command? Hope anyone knows! Kind regards, Raymond ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-psc] Fwd: Documentation writing
Hi all (sorry for the cross-posting but it's because the call was made if I'm not wrong on all the three channels) Thanks to those that already applied and happy to see that Documentation repo will likely be lively in upcoming weeks. If that can help to attract more people, these are some of the main areas I feel the documentation is far behind (or the features I think would be worth describing in priority in official manuals - not sorted): * 3D formats and features: up to now no word has been written about although I think this could be an attractive feature * the user profiles behavior: another big change on the settings philosophy that impact everybody and would deserve some literature * the processing system and particularly "graphical modeler": The algorithms, and particularly native ones, are well covered, But the Processing options and more important the modelers are less behind imho * the QGIS Server: can't really tell how the doc is in this area but there are a lot of pending issues in the repo * the print layout reporting * attribute table and custom forms/widgets * unfortunately as usual, the PyQGIS doc ... * ... and the data source manager dialog (particularly some of the tabs at the bottom of the dialog) * and of course, any other area you think you know better... Some ideas for those willing to apply and write docs. Hope that helps, Harrissou Le mer. 19 sept. 2018 à 11:27, Paolo Cavallini a écrit : > One more: > Frank Sokolic > * I am interested in updating grammar and writing style as I am a native > English speaker > * I can take responsibility for any part of the documentation that you > allocate to me > * I am available for 20 hours to help with documentation. > > > Il 09/19/2018 09:31 AM, Régis Haubourg ha scritto: > > Hi all, > > Paul Blottiere is also available to work on QGIS server documentation. > > Best regards > > Régis > > On 19/09/2018 07:26, Paolo Cavallini wrote: > > Hi all, > > this is what we have for now: > Tim Sutton > available to do general documentation writing and English review of > submitted documentation > > Tudor barascu > available to write and review documentation. > At first I would like to focus and finish whatever is left from the > server side > > matteo > Both write and review. > > Yves Jacolin > review some PR > > Alexandre Neto > some surgical interventions instead and some reviews when possible > > David Forel > I am open to reviewing anyone's English text > > Not much in effect. Let's wait a few days and then we can start budgeting > and assigning tasks. > All the best. > > Messaggio Inoltrato > Oggetto: [QGIS-Developer] Documentation writing > Data: Mon, 17 Sep 2018 11:30:26 +0200 > Mittente: Paolo Cavallini > A: qgis-developer > > > Hi all, > > as you know, next LTR (3.4) is coming soon. Its documentation is lagging > behind, so the PSC decided to invest in updating it. Those of you who > are interested in writing it please reply to this message stating; > > * which part of documentation you are interested in updating > > * if you can take the responsibility for completing it, or if it's just > for a part of it > > * for how many hours (approx) you are available. > > This will allow us to correctly budget this task. We welcome anyone, and > will give priority to those who already wrote substantial parts of the > current docs. > > All the best, and thanks. > > -- > Paolo Cavallini - www.faunalia.euQGIS.ORG > Chair:http://planet.qgis.org/planet/user/28/tag/qgis%20board/ > > > ___ > QGIS-Developer mailing listqgis-develo...@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > ___ > Qgis-psc mailing > listQgis-psc@lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/qgis-psc > > > -- > Open Source GIS Expert / Water management > > mail: regis.haubo...@oslandia.com > tél: 0033 184 257 870 > -http://oslandia.com/ > > OSLANDIA IS AN INNOVATIVE COMPANY SPECIALIZED IN GIS ARCHITECTURE. WE > PROVIDE SERVICE ON OPEN SOURCE SOFTWARE FOR WHICH WE ARE EDITORS OR > RECOGNIZED EXPERTS. > > > > ___ > Qgis-psc mailing > listQgis-psc@lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/qgis-psc > > > -- > Paolo Cavallini - www.faunalia.euQGIS.ORG > Chair:http://planet.qgis.org/planet/user/28/tag/qgis%20board/ > > ___ > Qgis-psc mailing list > qgis-...@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/qgis-psc ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
[QGIS-Developer] Plugin [1410] ImportPhotos approval notification.
Plugin ImportPhotos approval by pcav. The plugin version "[1410] ImportPhotos 1.4" is now approved Link: http://plugins.qgis.org/plugins/ImportPhotos/ ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
>> We use a direct port from GRASS: This may also be caused by: /* * From original rttopo documentation: * Tested against: * http://mascot.gdbc.gov.bc.ca/mascot/util1b.html * and * http://www.ga.gov.au/nmd/geodesy/datums/vincenty_direct.jsp */ QgsPointXY QgsDistanceArea::computeSpheroidProject( const QgsPointXY , double distance, double azimuth ) const which is used in rtspheroid.c when GeographicLib is not avaliable. Mark ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
It's not a small area, that's why I have been nitpicking ellipsoid area calculation algorithms! I did end up doing the calculations with geographiblib to get a reference to judge various other calculations by. It's a pain in the butt to extract the data from a polygon shapefile (or whatever) and format it to suit the planimeter app of geographiclib. It would be so much cooler if I could get the same results by clicking info on a polygon in QGIS :-) /Kristian -Oprindelig meddelelse- Fra: Nyall Dawson Sendt: 25. september 2018 09:07 Til: Kristian Evers Cc: Paolo Cavallini ; qgis-developer Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 On Tue, 25 Sep 2018 at 16:59, Kristian Evers wrote: > > Hi Paolo, > > I have some rought notes that I can try to polish up a bit and share here. > I'll see if I can find the time for that today. I didn't get to the bottom of > the problem but I am leaning towards the issue being that QGIS uses an > inferior algorithm to determine geodesics. Unfortunately I couldn't find out > from either the source code or the documentation which algorithm is used. > As far as I remember it differs from the otherwise popular algorithm by > Vincenty. That may be because a different algorithm is used or the > Implementation is wrong. > > I'll get back with a better write-up later and some test data and results. We use a direct port from GRASS: https://github.com/qgis/QGIS/blob/master/src/core/qgsdistancearea.cpp#L690 vs GRASS upstream: https://trac.osgeo.org/grass/browser/grass/trunk/lib/gis/area_poly1.c?rev=71260 It's not very stable for very small areas -- better to use cartesian calculations there. Or bring in geographiclib and punt the responsibility elsewhere ;) Nyall > > /Kristian > > -Oprindelig meddelelse- > Fra: QGIS-Developer På vegne af > Paolo Cavallini > Sendt: 25. september 2018 08:23 > Til: qgis-developer@lists.osgeo.org > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > Hi Kristian, > > > Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > > > > On a related note, I have been meaning to raise a similar issue based > > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > > A colleague of mine came across some differences between QGIS and > > CARIS LOTS while doing area calculations in relation to a border > > dispute at sea. After that I tested several popular closed source GIS > > apps and they all performed better than QGIS. > this is worth exploring in detail. could you please be more specific? do > you have a test case? could you share the results, or give us a way to > replicate them? > Thanks. > > -- > Paolo Cavallini - www.faunalia.eu > QGIS.ORG Chair: > http://planet.qgis.org/planet/user/28/tag/qgis%20board/ > > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
On Tue, 25 Sep 2018 at 16:59, Kristian Evers wrote: > > Hi Paolo, > > I have some rought notes that I can try to polish up a bit and share here. > I'll see if I can find the time for that today. I didn't get to the bottom of > the problem but I am leaning towards the issue being that QGIS uses an > inferior algorithm to determine geodesics. Unfortunately I couldn't find out > from either the source code or the documentation which algorithm is used. > As far as I remember it differs from the otherwise popular algorithm by > Vincenty. That may be because a different algorithm is used or the > Implementation is wrong. > > I'll get back with a better write-up later and some test data and results. We use a direct port from GRASS: https://github.com/qgis/QGIS/blob/master/src/core/qgsdistancearea.cpp#L690 vs GRASS upstream: https://trac.osgeo.org/grass/browser/grass/trunk/lib/gis/area_poly1.c?rev=71260 It's not very stable for very small areas -- better to use cartesian calculations there. Or bring in geographiclib and punt the responsibility elsewhere ;) Nyall > > /Kristian > > -Oprindelig meddelelse- > Fra: QGIS-Developer På vegne af > Paolo Cavallini > Sendt: 25. september 2018 08:23 > Til: qgis-developer@lists.osgeo.org > Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 > > Hi Kristian, > > > Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > > > > On a related note, I have been meaning to raise a similar issue based > > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > > A colleague of mine came across some differences between QGIS and > > CARIS LOTS while doing area calculations in relation to a border > > dispute at sea. After that I tested several popular closed source GIS > > apps and they all performed better than QGIS. > this is worth exploring in detail. could you please be more specific? do > you have a test case? could you share the results, or give us a way to > replicate them? > Thanks. > > -- > Paolo Cavallini - www.faunalia.eu > QGIS.ORG Chair: > http://planet.qgis.org/planet/user/28/tag/qgis%20board/ > > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > ___ > QGIS-Developer mailing list > QGIS-Developer@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] is_layer_active expression
On Tue, 25 Sep 2018 at 16:43, Otto Dassau wrote: > > thanks for the info Nyall! Ok, PR opened. https://github.com/qgis/QGIS/pull/8016 But for reference -- I think what's going to be more useful for layout use is the 3.4 @map_layers variable. As noted in the earlier reply, some functions are context dependent, and is_layer_visible is one of these. So in 3.4 it will work *within* a layout item map, it won't allow you to e.g. have a label item outside the map change its content based on is_layer_visible. On the other hand, you *can* retrieve expression variables (not functions!) from another layout item, using the item_variables function! So you can build the expression: map_get( item_variables( 'Your_Map_ID' ), 'map_layers' ) To retrieve a list of map layers within the Your_Map_Id map item, and this expression will work anywhere inside the layout! (i.e. labels, data defined expressions, etc). One intended use case for this is to allow labels with expressions like: array_to_string( array_foreach(map_get( item_variables( 'Your_Map_ID' ), 'map_layers' ), layer_property(@element, 'name')), ',' ) To get a nice comma separated list of all layers included in the map item. (Admittedly, that expression is quite complex, but if you pick it apart piece by piece you should be able to decipher it!). Nyall > > Regards, > Otto > > Am Tue, 25 Sep 2018 16:37:38 +1000 > schrieb Nyall Dawson : > > > On Mon, 24 Sep 2018 at 19:20, Otto Dassau wrote: > > > > > > Dear Devs, > > > > > > in QGIS 3 I found the expression "is_layer_active" within the copyright > > > decoration very useful. I would like to use this expression also within > > > the print composer, but it seems to be not available there. > > > > Confirmed -- fix incoming! > > > > > Is this correct, are expressions not available all over QGIS within the > > > expression builder? > > > > Some expression functions/variables are "context dependent". E.g. > > is_layer_visible doesn't make any sense in expressions which aren't > > directly associated with a map. So the function won't be available as > > for expressions used as a field default value, or for a layout text > > label (since the layout may have multiple maps, each with a different > > layer set, and a label isn't linked to any map item in particular!). > > > > > And how can I get this expression working for the print composer as > > > well? > > > > Wait for 3.4 ;) > > > > Nyall > ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
Hi Paolo, I have some rought notes that I can try to polish up a bit and share here. I'll see if I can find the time for that today. I didn't get to the bottom of the problem but I am leaning towards the issue being that QGIS uses an inferior algorithm to determine geodesics. Unfortunately I couldn't find out from either the source code or the documentation which algorithm is used. As far as I remember it differs from the otherwise popular algorithm by Vincenty. That may be because a different algorithm is used or the Implementation is wrong. I'll get back with a better write-up later and some test data and results. /Kristian -Oprindelig meddelelse- Fra: QGIS-Developer På vegne af Paolo Cavallini Sendt: 25. september 2018 08:23 Til: qgis-developer@lists.osgeo.org Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 Hi Kristian, Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > On a related note, I have been meaning to raise a similar issue based > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > A colleague of mine came across some differences between QGIS and > CARIS LOTS while doing area calculations in relation to a border > dispute at sea. After that I tested several popular closed source GIS > apps and they all performed better than QGIS. this is worth exploring in detail. could you please be more specific? do you have a test case? could you share the results, or give us a way to replicate them? Thanks. -- Paolo Cavallini - www.faunalia.eu QGIS.ORG Chair: http://planet.qgis.org/planet/user/28/tag/qgis%20board/ ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] is_layer_active expression
thanks for the info Nyall! Regards, Otto Am Tue, 25 Sep 2018 16:37:38 +1000 schrieb Nyall Dawson : > On Mon, 24 Sep 2018 at 19:20, Otto Dassau wrote: > > > > Dear Devs, > > > > in QGIS 3 I found the expression "is_layer_active" within the copyright > > decoration very useful. I would like to use this expression also within > > the print composer, but it seems to be not available there. > > Confirmed -- fix incoming! > > > Is this correct, are expressions not available all over QGIS within the > > expression builder? > > Some expression functions/variables are "context dependent". E.g. > is_layer_visible doesn't make any sense in expressions which aren't > directly associated with a map. So the function won't be available as > for expressions used as a field default value, or for a layout text > label (since the layout may have multiple maps, each with a different > layer set, and a label isn't linked to any map item in particular!). > > > And how can I get this expression working for the print composer as > > well? > > Wait for 3.4 ;) > > Nyall ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] is_layer_active expression
On Mon, 24 Sep 2018 at 19:20, Otto Dassau wrote: > > Dear Devs, > > in QGIS 3 I found the expression "is_layer_active" within the copyright > decoration very useful. I would like to use this expression also within the > print composer, but it seems to be not available there. Confirmed -- fix incoming! > Is this correct, are expressions not available all over QGIS within the > expression builder? Some expression functions/variables are "context dependent". E.g. is_layer_visible doesn't make any sense in expressions which aren't directly associated with a map. So the function won't be available as for expressions used as a field default value, or for a layout text label (since the layout may have multiple maps, each with a different layer set, and a label isn't linked to any map item in particular!). > And how can I get this expression working for the print composer as well? Wait for 3.4 ;) Nyall ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0
Hi Kristian, Il 09/25/2018 07:24 AM, Kristian Evers ha scritto: > > > On a related note, I have been meaning to raise a similar issue based > on QGIS’s not so accurate polygon-area-on-the-ellipsoid calculations. > A colleague of mine came across some differences between QGIS and > CARIS LOTS while doing area calculations in relation to a border > dispute at sea. After that I tested several popular closed source GIS > apps and they all performed better than QGIS. this is worth exploring in detail. could you please be more specific? do you have a test case? could you share the results, or give us a way to replicate them? Thanks. -- Paolo Cavallini - www.faunalia.eu QGIS.ORG Chair: http://planet.qgis.org/planet/user/28/tag/qgis%20board/ ___ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
