[R-sig-Geo] sp/rgdal workflows with PROJ >= 6 and GDAL >= 3

Lorenzo Busetto |bu@ett @end|ng |rom gm@||@com
Sat Nov 30 17:26:35 CET 2019


Thanks. I'll check it out on Monday and let you know if there are any
issues.

Lorenzo

On Sat, 30 Nov 2019, 11:53 Roger Bivand, <Roger.Bivand using nhh.no> wrote:

> Streaming link now published (thanks to Arild Schanke), only live when
> transmission active.
>
> Roger
>
> On Fri, 29 Nov 2019, Roger Bivand wrote:
>
> > Thanks, we use the local, institutional interface which provides the
> > quality we delivered at the 2014 Geostat summer school. The link will be
> > posted on
> > https://rsbivand.github.io/ECS530_h19/streaming_ecs530_h19.html when
> > available (delayed because I've been off work). We'll just have to use
> > Monday's classes to check that things are working, feedback info in the
> > link above.
> >
> > Roger
> >
> > --
> > Roger Bivand
> > Norwegian School of Economics
> > Helleveien 30, 5045 Bergen, Norway
> > Roger.Bivand using nhh.no
> >
> >
> > ________________________________________
> > Fra: Lorenzo Busetto <lbusett using gmail.com>
> > Sendt: fredag 29. november 2019 18.30
> > Til: Roger Bivand
> > Kopi: r-sig-geo using r-project.org
> > Emne: Re: [R-sig-Geo] sp/rgdal workflows with PROJ >= 6 and GDAL >= 3
> >
> > Dear Roger,
> >
> >    I'd be very interested in participating to the stream talk. Is it
> confirmed?
> >
> > Concerning testing the connection, I'd be happy to do it but I do not
> know how much I will be available online in the coming days. You can drop
> me a mail/DM on twitter, and if I am available I'll gladly help.
> >
> > Concerning technology, Zoom usually works quite well (https://zoom.us/<
> https://zoom.us/ent?zcid=3172>)
> >
> >   regards,
> >
> > Lorenzo
> >
> > On Sat, 23 Nov 2019 at 13:04, Roger Bivand <Roger.Bivand using nhh.no<mailto:
> Roger.Bivand using nhh.no>> wrote:
> > A description of the status now with regard to a prototype resolution is
> > online at:
> >
> > https://rsbivand.github.io/ECS530_h19/ECS530_III.html
> >
> > I'm planning to stream a talk about this at 09:15-11:00 CET on Tuesday 3
> > December. I need a volunteer to test the streaming link in advance during
> > next week. I'm unsure which technology to use for remote participants to
> > provide feedback.
> >
> > Contributions/comments welcome!
> >
> > Roger
> >
> >
> > On Fri, 15 Nov 2019, Roger Bivand wrote:
> >
> >> The development version of rgdal on R-Forge is now at rev 894, and is
> now
> >> ready for trying out with PROJ6/GDAL3 workflows, and workflows that may
> >> migrate within 6 months to modern CRS representations. The motivating
> RFC is
> >> also updated to cover coordinate operations, the use of prepared
> >> (pre-searched) coordinate operations, and should be read carefully by
> anyone
> >> using rgdal::spTransform(). Note further that rgdal::project() will not
> be
> >> adapted for PROJ6, and is effectively deprecated.
> >>
> >> I'll be running reverse dependency checks, and may be bugging package
> >> maintainers. I would really prefer that mainainers of packages using
> >> spTransform() checked themselves and joined this thread or the
> associated
> >> twitter thread:
> https://twitter.com/RogerBivand/status/1194586193108914177
> >>
> >> Be ready for modern PROJ and GDAL, they are already being deployed
> across
> >> open source geospatial software, like GRASS, QGIS, pyproj, spatialite
> etc.
> >>
> >> Waiting, hopefully not in vain, for contributions.
> >>
> >> Roger
> >>
> >> On Wed, 13 Nov 2019, Roger Bivand wrote:
> >>
> >>>  And this link explains the CDN proposal for grid distribution:
> >>>
> >>>  https://www.spatialys.com/en/crowdfunding/
> >>>
> >>>  Roger
> >>>
> >>>  On Wed, 13 Nov 2019, Roger Bivand wrote:
> >>>
> >>>>   Because PROJ >= 6 and GDAL >= 3 change the way that PROJ strings
> >>>>   (representations of coordinate reference systems) are handled,
> steps are
> >>>>   being taken to find ways to adapt sp/rgdal workflows. A current
> proposal
> >>>>   is to store the WKT2_2018 string as a comment to CRS objects as
> defined
> >>>>   in
> >>>>   the sp package.
> >>>>
> >>>>   A draft development-in-progress version of rgdal is available at
> >>>>   https://r-forge.r-project.org/R/?group_id=884, and for sp at
> >>>>   https://github.com/rsbivand/sp (this version of sp requires rgdal
> >=
> >>>>   1.5-1). This adds the WKT comments to CRS objects on reading vector
> and
> >>>>   raster data sources, and uses WKT comments if found when writing
> vector
> >>>>   and raster objects (or at least does as far as I've checked,
> possibly
> >>>>   fragile).
> >>>>
> >>>>   An RFC with tersely worked cases for using CRS object comments to
> carry
> >>>>   WKT strings but maintaining full backward compatibility is online at
> >>>>   http://rgdal.r-forge.r-project.org/articles/PROJ6_GDAL3.html.
> >>>>
> >>>>   If you have other ideas or concerns about trying to use this
> mechanism
> >>>>   for
> >>>>   sp CRS objects, please contribute at your earliest convenience.
> >>>>
> >>>>   http://rgdal.r-forge.r-project.org/reference/list_coordOps.html
> shows
> >>>>   the
> >>>>   beginning of the next step, to query transformation operations to
> find
> >>>>   viable coordinate operation pipelines.
> >>>>
> >>>>   I'm assuming that the previous behaviour (transform without
> considering
> >>>>   accuracy with whatever is to hand) is not viable going forward, and
> that
> >>>>   we will need two steps: list coordinate operations between source
> and
> >>>>   target CRS (using the WKT comments as better specifications than the
> >>>>   PROJ
> >>>>   strings), possibly intervene manually to install missing grids, then
> >>>>   undertake the coordinate operation.
> >>>>
> >>>>   The fallback may be simply to choose the least inaccurate available
> >>>>   coordinate operation, but this should be a fallback. This means
> that all
> >>>>   uses of spTransform() will require intervention.
> >>>>
> >>>>   Is this OK (it is tiresome but modernises workflows once), or is it
> not
> >>>>   OK
> >>>>   (no user intervention is crucial)?
> >>>>
> >>>>   These behaviours may be set in an option, so that package
> maintainers
> >>>>   and
> >>>>   users may delay modernisation, but all are undoubtedly served by
> rapid
> >>>>   adaptation (GRASS 7.8.1 released yesterday, libspatialite, pyproj,
> QGIS
> >>>>   development versions all state that they list candidate coordinate
> >>>>   operations).
> >>>>
> >>>>   We cannot ship all the grids, they are very bulky, and probably
> nobody
> >>>>   needs sub-metre accuracy world-wide. Work in PROJ is starting to
> create
> >>>>   a
> >>>>   content delivery network for trusted download and mechanisms for
> >>>>   registering downloaded grids on user platforms. We would for
> example not
> >>>>   want Windows users of rgdal and sf to have to download the same grid
> >>>>   twice.
> >>>>
> >>>>   Comments welcome here and at
> >>>>   https://github.com/r-spatial/discuss/issues/28 or
> >>>>   https://github.com/r-spatial/sf/issues/1187
> >>>>
> >>>>   Roger
> >>>>
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Roger Bivand
> > Department of Economics, Norwegian School of Economics,
> > Helleveien 30, N-5045 Bergen, Norway.
> > voice: +47 55 95 93 55; e-mail: Roger.Bivand using nhh.no<mailto:
> Roger.Bivand using nhh.no>
> > https://orcid.org/0000-0003-2392-6140
> > https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo using r-project.org<mailto:R-sig-Geo using r-project.org>
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
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> >
>
> --
> Roger Bivand
> Department of Economics, Norwegian School of Economics,
> Helleveien 30, N-5045 Bergen, Norway.
> voice: +47 55 95 93 55; e-mail: Roger.Bivand using nhh.no
> https://orcid.org/0000-0003-2392-6140
> https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
>

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