Re: [Qgis-user] Problems with re-projection in QGIS>2.2 on MacOS
Thanks! That did the trick Peter Aldhous, PhD Science journalist Contributor, MATTER <https://www.medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> On 7/1/14, 11:23 AM, Larry Shaffer wrote: > Hi Peter, > > On Sun, Jun 29, 2014 at 9:35 AM, Peter Aldhous <mailto:pe...@peteraldhous.com>> wrote: > > Yes, on my system the problem also resolves on zooming - although > I'd only use Robinson for a global view. > > However, I have no problem with Google Mercator. > > Would really like to know how to fix this! > > > Try turning off 'Simplify geometry' for the layer (in layer > properties) [0]. For new projects, not existing ones, the default > behavior in QGIS 2.4 can now be controlled by a checkbox in Options -> > Rendering (I think it's the Rendering tab, not at a computer right > now). Then, you can selectively turn it on for layers where > simplification would help speed up rendering. > > [0] http://gis.stackexchange.com/a/100333/6725 > > Regards, > > Larry Shaffer > Dakota Cartography > Black Hills, South Dakota > > > > > Peter Aldhous, PhD > Science journalist > Contributor, MATTER <https://www.medium.com/matter> > phone: 415 800 3471 > cell: 415 503 7323 > email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> > web: www.peteraldhous.com <http://www.peteraldhous.com/> > twitter: @paldhous <https://twitter.com/paldhous> > > On 6/29/14, 7:57 AM, Micha Silver wrote: >> I can verify this same behavior on Win7 with QGIS 2.4 64b. I >> think it has to do with the shapes crossing the 180ยบ line. If you >> zoom in to a smaller area that includes only countries in one >> hemisphere, the borders look OK. Also, it's not only Robinson and >> Mollweide: any global projection will show strange trapezoids >> (even "Google" mercator) >> I also see that if you use the *spatialite database file* from >> naturalearthdata.org <http://naturalearthdata.org> this problem >> disappears. You can switch to other world projections with no >> problem. >> >> On 29/06/2014 16:59, Peter Aldhous wrote: >>> I don't think the image came through, but the problem is that >>> every polygon ends up as a trapezoid, so I end up with a >>> collection of overlapping trapezoids >>> >>> Peter Aldhous, PhD >>> Science journalist >>> Contributor, MATTER <https://www.medium.com/matter> >>> phone: 415 800 3471 >>> cell: 415 503 7323 >>> email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> >>> web: www.peteraldhous.com <http://www.peteraldhous.com/> >>> twitter: @paldhous <https://twitter.com/paldhous> >>> >>> On 6/29/14, 6:54 AM, Peter Aldhous wrote: >>>> Hi all, >>>> >>>> I'm using the KyngChaos install of QGIS on the Mac (Mavericks >>>> and Lion, on different machines), and I've been having problems >>>> with projections including Robinson and Mollweide from QGIS >>>> 2.2 onwards. >>>> >>>> Everything was fine in QGIS 2.0, but in 2.2 and 2.4, >>>> re-projecting a world Natural Earth shapefile to a Robinson >>>> projection, for example, gives this: >>>> >>>> Any idea what might be going on, and how to fix it? >>>> >>>> Thanks, >>>> >>>> >>>> -- >>>> Peter Aldhous, PhD >>>> Science journalist >>>> Contributor, MATTER <https://www.medium.com/matter> >>>> phone: 415 800 3471 >>>> cell: 415 503 7323 >>>> email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> >>>> web: www.peteraldhous.com <http://www.peteraldhous.com/> >>>> twitter: @paldhous <https://twitter.com/paldhous> >>>> >>> >>> >>> >>> This mail was received via Mail-SeCure System. >>> >>> >>> ___ >>> Qgis-user mailing list >>> Qgis-user@lists.osgeo.org <mailto:Qgis-user@lists.osgeo.org> >>> http://lists.osgeo.org/mailman/listinfo/qgis-user >>> This mail was received via Mail-SeCure System. >>> >>> >> >> >> -- >> Micha Silver >> GIS Consulting >> 052-3665918 >> http://www.surfaces.co.il > > > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org <mailto: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] reposting q on reprojection problem in QGIS > 2.0
Dear Andre, Thanks for your reply. I was optimistic that this would work, but sadly it does not. I've tried creating various polygons, and running either clip or difference. Even if I cut the world shapefile 5 degrees away from 180E/W, I'm still getting the bizarre trapezoid behavior on reprojection to Robinson in QGIS. ogr3ogr in the command line works fine, and there I don't need to clip, the reprojection works and the shapefile loads perfectly in QGIS. So this is fine for my purposes, but it does seem that something has gone awry with reprojection in the latest version of QGIS for the Mac. Which will be a shame when I come to teach it. Best wishes, Peter Peter Aldhous, PhD Science journalist Contributor, MATTER <https://www.medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] reposting q on reprojection problem in QGIS > 2.0
Hi all, Apologies for reviving this thread (below), but does anyone have a solution other than using a different data format? I ask because I will be do some teaching using QGIS and want to work with shapefiles for that. This is a problem that's emerged for me only with recent versions of QGIS, so something must have changed to cause the behavior. Might it be at the level of GDAL? Best wishes, Peter -- Peter Aldhous, PhD Science journalist Contributor, MATTER <https://medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> I can verify this same behavior on Win7 with QGIS 2.4 64b. I think it has to do with the shapes crossing the 180^(o) line. If you zoom in to a smaller area that includes only countries in one hemisphere, the borders look OK. Also, it's not only Robinson and Mollweide: any global projection will show strange trapezoids (even "Google" mercator) I also see that if you use the *spatialite database file* from naturalearthdata.org this problem disappears. You can switch to other world projections with no problem. On 29/06/2014 16:59, Peter Aldhous wrote: > I don't think the image came through, but the problem is that every > polygon ends up as a trapezoid, so I end up with a collection of > overlapping trapezoids > > Peter Aldhous, PhD > Science journalist > Contributor, MATTER <https://www.medium.com/matter> > phone: 415 800 3471 > cell: 415 503 7323 > email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> > web: www.peteraldhous.com <http://www.peteraldhous.com/> > twitter: @paldhous <https://twitter.com/paldhous> > > On 6/29/14, 6:54 AM, Peter Aldhous wrote: >> Hi all, >> >> I'm using the KyngChaos install of QGIS on the Mac (Mavericks and >> Lion, on different machines), and I've been having problems with >> projections including Robinson and Mollweide from QGIS 2.2 onwards. >> >> Everything was fine in QGIS 2.0, but in 2.2 and 2.4, re-projecting a >> world Natural Earth shapefile to a Robinson projection, for example, >> gives this: >> >> Any idea what might be going on, and how to fix it? >> >> Thanks, >> >> >> -- >> Peter Aldhous, PhD >> Science journalist >> Contributor, MATTER <https://www.medium.com/matter> >> phone: 415 800 3471 >> cell: 415 503 7323 >> email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> >> web: www.peteraldhous.com <http://www.peteraldhous.com/> >> twitter: @paldhous <https://twitter.com/paldhous> >> ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Problems with re-projection in QGIS>2.2 on MacOS
Yes, on my system the problem also resolves on zooming - although I'd only use Robinson for a global view. However, I have no problem with Google Mercator. Would really like to know how to fix this! Peter Aldhous, PhD Science journalist Contributor, MATTER <https://www.medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> On 6/29/14, 7:57 AM, Micha Silver wrote: I can verify this same behavior on Win7 with QGIS 2.4 64b. I think it has to do with the shapes crossing the 180^(o) line. If you zoom in to a smaller area that includes only countries in one hemisphere, the borders look OK. Also, it's not only Robinson and Mollweide: any global projection will show strange trapezoids (even "Google" mercator) I also see that if you use the *spatialite database file* from naturalearthdata.org this problem disappears. You can switch to other world projections with no problem. On 29/06/2014 16:59, Peter Aldhous wrote: I don't think the image came through, but the problem is that every polygon ends up as a trapezoid, so I end up with a collection of overlapping trapezoids Peter Aldhous, PhD Science journalist Contributor, MATTER <https://www.medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> On 6/29/14, 6:54 AM, Peter Aldhous wrote: Hi all, I'm using the KyngChaos install of QGIS on the Mac (Mavericks and Lion, on different machines), and I've been having problems with projections including Robinson and Mollweide from QGIS 2.2 onwards. Everything was fine in QGIS 2.0, but in 2.2 and 2.4, re-projecting a world Natural Earth shapefile to a Robinson projection, for example, gives this: Any idea what might be going on, and how to fix it? Thanks, -- Peter Aldhous, PhD Science journalist Contributor, MATTER <https://www.medium.com/matter> phone: 415 800 3471 cell: 415 503 7323 email: pe...@peteraldhous.com <mailto:pe...@peteraldhous.com> web: www.peteraldhous.com <http://www.peteraldhous.com/> twitter: @paldhous <https://twitter.com/paldhous> This mail was received via Mail-SeCure System. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user This mail was received via Mail-SeCure System. -- Micha Silver GIS Consulting 052-3665918 http://www.surfaces.co.il ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
