May be tested against test dataset provided by werner macho and Giovanni Manghi?
On Tuesday, 24 November 2015, Matthias Kuhn <[email protected]> wrote: > Thank you Marco, > > Are you confident that these are the only places that need changes, so > does this mean that there is no more reason for a warning and we just need > a quick point release? > I applied the same to processing and did some changes to your fix to make > it work also for union and clip. > > Regards > Matthias > > On 11/24/2015 04:58 PM, Neumann, Andreas wrote: > > Thank you Marco! Much appreciated. > > Andreas > > On 2015-11-24 16:36, Marco Hugentobler wrote: > > Hi all > > I had a detailed look with the debugger at what happens in the different > versions. It turned out fTools does indeed handle geometry collections, but > assumed a geometry collection has wkb type 'unknown' (which was true <= > 2.8, but now geometry collections are not unknown anymore). Commit > <https://github.com/qgis/QGIS/commit/594fafe73b80d91d94b962c2e51aea0b0168a08a> > https://github.com/qgis/QGIS/commit/594fafe73b80d91d94b962c2e51aea0b0168a08a > should solve the issue and bring back the old behaviour. > > Regards, > Marco > > > > On 24.11.2015 11:29, Marco Hugentobler wrote: > > On 24.11.2015 11:13, Matthias Kuhn wrote: > > Hi Marco > > On 11/24/2015 11:01 AM, Marco Hugentobler wrote: > > Hi Alessandro, Matthias > > >Is there no requirement for multi types? > > Afaik, the problem for f-tools are not the multi types, but only the > geometry collections (containing geometries with different shape type). In > my experience, if geos returns a geometry collection, it usually contains > one 'expected' geometry and the others are slivers (@strk, please correct > me if wrong). > > > I was mostly thinking about collections that contain a multitype with > several parts which are not considered slivers. This seems to be a very > valid scenario. > > > It is, but it was also not handled by f-tools <= 2.8. > > > > >Based on what indicator should be chosen what to extract? Try polygons > first, if there are none try lines, if there are none take points? > > One possibility would be to pass the expected shapetype (Point / Line / > Polygon) to the function and take the best candidate (e.g. longest line, > largest polygon area). > > > Before the geometry changes, the algorithms were able to provide the > results without this additional information. How was that done? > > > Not sure. Maybe the logic in the geos -> QgsGeometry conversion handled > the collections differently. > > > Regards, > Marco > > > > > > >How much effort (in time) do you think is required to implement this fix? > > Difficult to estimate. It seems straightforward to implement the > extraction function. Then it needs to be called by the f-tools internally > and be tested with a few examples. If unit tests are required (as mentioned > by Alessandro), this seems to be the most time consuming task to me. > > Unit Tests for processing are on my todo list anyway (I think as a psc > member you should have voted for that ;) ) > > Matthias > > > Regards, > Marco > > On 24.11.2015 10:42, Matthias Kuhn wrote: > > Hi Marco > > Good to have your feedback, you probably know the problem best. > > On 11/24/2015 09:28 AM, Marco Hugentobler wrote: > > Hi > > >ad issue 1: update fTools to warn users when some features cause problems > >ad issue 2: quick fix fTools to convert geometry collections to single > geometry types > > A function that takes a geometry type and extracts the longest line / the > largest polygon / the first point from the geometry collection should be > straightforward to do. > > > Is there no requirement for multi types? > Based on what indicator should be chosen what to extract? Try polygons > first, if there are none try lines, if there are none take points? > > > >These fixes/updates would be made available as fTools updates via the > plugin installer asap > > If the fix does not take too long, we probably don't need a warning at all. > > > How much effort (in time) do you think is required to implement this fix? > > Regards, > Matthias > > > Regards, > Marco > > On 23.11.2015 21:35, Anita Graser wrote: > > Hi, > > If you are following the psc list, you've probably seen the thread > discussing current shortcomings of ftools ( > <http://lists.osgeo.org/pipermail/qgis-psc/2015-November/003623.html> > http://lists.osgeo.org/pipermail/qgis-psc/2015-November/003623.html) > > In short, the key issues are: > 1. When ftools encounter issues with certain features, warning messages > get written to the log but this is largely hidden from users since they > would actively have to actively monitor the log. The problematic features > are then missing from the results but this is not always obvious. > 2. The above issue is more common now (since 2.10) since underlying > libraries more often (and correctly so) produce geometry collections as > outputs. These geometry collections are not handled well by the current > ftools code which is much older. > > To address these issues, the following suggestions have been made so far: > ad issue 1: update fTools to warn users when some features cause problems > ad issue 2: quick fix fTools to convert geometry collections to single > geometry types > > For the warnings, there's already a first PR draft > <https://github.com/qgis/QGIS/pull/2432> > https://github.com/qgis/QGIS/pull/2432 which needs to be fleshed out. > > These fixes/updates would be made available as fTools updates via the > plugin installer asap. > > If you have ideas how to handle this efficiently or have already > implemented code that addresses similar issues, let us know. > > It would be good to have a quick discussion in order to be able to provide > improvements fast. > > Best wishes, > Anita > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > -- > Dr. Marco Hugentobler > Sourcepole - Linux & Open Source Solutions > Weberstrasse 5, CH-8004 Zürich, [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://www.sourcepole.ch > Technical Advisor QGIS Project Steering Committee > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > -- > Matthias Kuhn > OPENGIS.ch - https://www.opengis.ch > Spatial • (Q)GIS • PostGIS • Open Source > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > -- > Dr. Marco Hugentobler > Sourcepole - Linux & Open Source Solutions > Weberstrasse 5, CH-8004 Zürich, [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://www.sourcepole.ch > Technical Advisor QGIS Project Steering Committee > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > -- > Matthias Kuhn > OPENGIS.ch - https://www.opengis.ch > Spatial • (Q)GIS • PostGIS • Open Source > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > -- > Dr. Marco Hugentobler > Sourcepole - Linux & Open Source Solutions > Weberstrasse 5, CH-8004 Zürich, [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://www.sourcepole.ch > Technical Advisor QGIS Project Steering Committee > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > -- > Dr. Marco Hugentobler > Sourcepole - Linux & Open Source Solutions > Weberstrasse 5, CH-8004 Zürich, [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://www.sourcepole.ch > Technical Advisor QGIS Project Steering Committee > > > _______________________________________________ > Qgis-developer mailing list > [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > > > _______________________________________________ > Qgis-developer mailing [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer > > > -- > Matthias Kuhn > OPENGIS.ch - https://www.opengis.ch > Spatial • (Q)GIS • PostGIS • Open Source > > -- Luigi Pirelli ************************************************************************************************** * Boundless QGIS Support/Development: lpirelli AT boundlessgeo DOT com * LinkedIn: https://www.linkedin.com/in/luigipirelli * Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli * GitHub: https://github.com/luipir * Mastering QGIS: https://www.packtpub.com/application-development/mastering-qgis **************************************************************************************************
_______________________________________________ Qgis-developer mailing list [email protected] List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer
