[QGIS-Developer] Dropping the extra label placement algorithms?

Mon Jul 29 00:33:35 PDT 2019

Yes, if you consider trial and error a mindful method, I "use" label
placement algorithms when preparing a cartographic layout for printing.
I mainly work on geographic data and web output, so it's not frequent and I
follow the easy and dumb way: I swap algorithms, hoping for a result that
solves cluttering in the worst spots, until it fits – usually it fits here
and it's out of order elsewhere...
I generally criticise this approach, but when looking for a good
appearance, it seems bearable. Yes, I would need some more information to
do a better work. As already said, I think this is a cartographic issue
that can get more benefits by a better GIS approach. Label positioning is
not "substantial" but can exploit proper data. Say population for a
populated place. Using these algorithms on top of geometric-only data gives
little more than casual results.
I had the opportunity to weight the theory behind these methods starting
from the obituary of Mitchell Jay Feigenbaum by Maurizio Codogno on
ilPost.it that referenced the New York Times:
https://www.nytimes.com/2019/07/18/science/mitchell-feigenbaum-dead.html.
Looking to further developments, I think there is not a "best" algorithm,
but that it's useful to keep alternatives. I doubt the algorithms could
really work well without an interface that can reach useful data, but I
also think that keeping them available without any special interface could
keep them in a place that is not really influenced by the frequent
enhancements of QGIS.
c

On Mon, Jul 29, 2019 at 8:31 AM Nyall Dawson <nyall.dawson at gmail.com> wrote:

> On Mon, 29 Jul 2019 at 16:28, Carlo A. Bertelli (Charta s.r.l.)
> <carlo.bertelli at gmail.com> wrote:
> >
> > Label placement took a lot of time and efforts in the past and this is
> the outcome.
> > It's true, there is no real need for it while on screen, but it could be
> very useful in Layout. The problem is similar to generalisation, you need
> proper data to support label placement. Losing the relationship with real
> geographic objects, when exporting the layout in SVG or postscript, label
> placement takes time and needs cartographic expertise while changing the
> algorithm in Layout mode can help a lot.
>
> So - just to confirm -- you are actively changing that setting, and
> seeing useful results from different methods? If so, which do you use?
> Which give the best results? What's the trade off between them?
>
> Nyall
>
>
> > Keeping several algorithms in Layout could ease code maintenance while
> keeping all the advantages.
> > On the other hand, this needs some efforts on documentation and Anita's
> touch is really welcome here. Algorithms need reference but also a plain
> explanation in something that resembles a book. Someone developed a
> publishing business out of a GIS program... maybe this is too much and has
> already been done, but...
> > My two eurocents.
> > c
> >
> > On Mon, Jul 29, 2019 at 2:00 AM Nyall Dawson <nyall.dawson at gmail.com>
> wrote:
> >>
> >> On Fri, 26 Jul 2019 at 12:40, Nyall Dawson <nyall.dawson at gmail.com>
> wrote:
> >> >
> >> > Hey lists
> >> >
> >> > This was first discussed back in 2016 (see
> >> >
> http://osgeo-org.1560.x6.nabble.com/Removal-of-labeling-search-methods-td5262743.html
> ),
> >> > but would anyone object if the different labeling solution algorithms
> >> > eg "chain" / "pop music" / "falp" / etc were dropped, and we just
> >> > leave the existing default (chain)?
> >> >
> >> > I don't think ANYONE knows what these mean, and it's a heck of a lot
> >> > of code (which needs fixes) to cart around for no compelling reason
> >> > that I can see.
> >> >
> >> > I have no particular preference to any of the methods, so would
> >> > happily accept a different default if anyone out there can point to
> >> > which method is best!
> >> >
> >> > Googling pop music / tabu / chain only gives a handful of results
> >> > relating to QGIS labeling engine. And googling for "falp" sounds like
> >> > something that would get you flagged on your company's firewall.
> >> >
> >> > Does ANYONE understand or change this setting? Or would object to its
> >> > complete removal?
> >>
> >> PR at https://github.com/qgis/QGIS/pull/30960
> >>
> >> Last chance to save this setting!
> >>
> >> Nyall
> >> _______________________________________________
> >> QGIS-Developer mailing list
> >> QGIS-Developer at lists.osgeo.org
> >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >
> >
> >
> > --
> >
> --------------------------------------------------------------------------
> > Carlo A. Bertelli
> >    Charta servizi e sistemi per il territorio e la storia ambientale srl
> >           Dipendenze del palazzo Doria,
> >           vc. alla Chiesa della Maddalena 9/2 16124      Genova (Italy)
> >           tel./fax +39(0)10 2475439  +39 0108566195  mobile:+39 393
> 1590711
> >    e-mail: bertelli at chartasrl.eu      http://www.chartasrl.eu
> >
> --------------------------------------------------------------------------
> >
> >
> >
>

-- 
--------------------------------------------------------------------------
Carlo A. Bertelli
   Charta servizi e sistemi per il territorio e la storia ambientale srl
          Dipendenze del palazzo Doria,
          vc. alla Chiesa della Maddalena 9/2 16124      Genova (Italy)
          tel./fax +39(0)10 2475439  +39 0108566195  mobile:+39 393 1590711
   e-mail: bertelli at chartasrl.eu      http://www.chartasrl.eu
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