[prev in list] [next in list] [prev in thread] [next in thread]
List: r-sig-geo
Subject: Re: [R-sig-Geo] Migrating from proj strings to WKT/EPSG
From: Ben Tupper <btupper () bigelow ! org>
Date: 2021-11-22 21:51:12
Message-ID: CALrbzg0qY6RM4dBZjC17FuF_05uuzM+sZKmPGovhZ8pFwCP80Q () mail ! gmail ! com
[Download RAW message or body]
Doh! Forehead slap! How the heck did I overlook that simple
solution. Thank you!
On Mon, Nov 22, 2021 at 2:51 PM Diego Hernangómez Herrero
<diego.hernangomezherrero@gmail.com> wrote:
>
> Hi Ben:
>
> I don't know if this is relevant for your question, but you can use proj4strings \
> with sf::st_crs() without using rgdal:
> ``` r
> proj <- "+proj=tmerc +datum=NAD83 +lon_0=-70d10 lat_0=42d50 k=.9999666666666667 \
> x_0=900000 y_0=0" sf::st_crs(proj)
>
> #> Coordinate Reference System:
> #> User input: +proj=tmerc +datum=NAD83 +lon_0=-70d10 lat_0=42d50 \
> k=.9999666666666667 x_0=900000 y_0=0 #> wkt:
> #> PROJCRS["unknown",
> #> BASEGEOGCRS["unknown",
> #> DATUM["North American Datum 1983",
> #> ELLIPSOID["GRS 1980",6378137,298.257222101,
> #> LENGTHUNIT["metre",1]],
> #> ID["EPSG",6269]],
> #> PRIMEM["Greenwich",0,
> #> ANGLEUNIT["degree",0.0174532925199433],
> #> ID["EPSG",8901]]],
> #> CONVERSION["unknown",
> #> METHOD["Transverse Mercator",
> #> ID["EPSG",9807]],
> #> PARAMETER["Latitude of natural origin",42.8333333333333,
> #> ANGLEUNIT["degree",0.0174532925199433],
> #> ID["EPSG",8801]],
> #> PARAMETER["Longitude of natural origin",-70.1666666666667,
> #> ANGLEUNIT["degree",0.0174532925199433],
> #> ID["EPSG",8802]],
> #> PARAMETER["Scale factor at natural origin",0.999966666666667,
> #> SCALEUNIT["unity",1],
> #> ID["EPSG",8805]],
> #> PARAMETER["False easting",900000,
> #> LENGTHUNIT["metre",1],
> #> ID["EPSG",8806]],
> #> PARAMETER["False northing",0,
> #> LENGTHUNIT["metre",1],
> #> ID["EPSG",8807]]],
> #> CS[Cartesian,2],
> #> AXIS["(E)",east,
> #> ORDER[1],
> #> LENGTHUNIT["metre",1,
> #> ID["EPSG",9001]]],
> #> AXIS["(N)",north,
> #> ORDER[2],
> #> LENGTHUNIT["metre",1,
> #> ID["EPSG",9001]]]]
> ```
>
>
> El lun, 22 nov 2021 a las 20:11, Ben Tupper (<btupper@bigelow.org>) escribió:
> >
> > Hello,
> >
> > I have a spatial mesh that provides the following CRS.
> >
> > proj <- "proj=tmerc +datum=NAD83 +lon_0=-70d10 lat_0=42d50
> > k=.9999666666666667 x_0=900000 y_0=0"
> >
> > To use this with the sf package it must be formed as Well Known Text
> > or a EPSG code. In this particular case there is no EPSG code in the
> > registry.
> >
> > My current workflow so I can use this data in sf is to leverage
> > showWKT() from the rgdal package to cast the proj string to WKT. The
> > following message is printed when the packages is loaded.
> >
> > > Please note that rgdal will be retired by the end of 2023, plan transition to \
> > > sf/stars/terra functions using GDAL and PROJ at your earliest convenience.
> >
> >
> > rgdal::showWKT(proj) |> sf::st_crs(wkt)
> >
> > #> Coordinate Reference System:
> > #> User input:
> > PROJCS["unknown",GEOGCS["unknown",DATUM["North_American_Datum_1983",SPHEROID["GRS
> > 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PR \
> > IMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTH \
> > ORITY["EPSG","9122"]]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_or \
> > igin",42.8333333333333],PARAMETER["central_meridian",-70.1666666666667],PARAMETER[ \
> > "scale_factor",0.999966666666667],PARAMETER["false_easting",900000],PARAMETER["fal \
> > se_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH]]
> > #> wkt:
> > #> PROJCRS["unknown",
> > #> BASEGEOGCRS["unknown",
> > #> DATUM["North American Datum 1983",
> > #> ELLIPSOID["GRS 1980",6378137,298.257222101,
> > #> LENGTHUNIT["metre",1]],
> > #> ID["EPSG",6269]],
> > #> PRIMEM["Greenwich",0,
> > #> ANGLEUNIT["degree",0.0174532925199433],
> > #> ID["EPSG",8901]]],
> > #> CONVERSION["unnamed",
> > #> METHOD["Transverse Mercator",
> > #> ID["EPSG",9807]],
> > #> PARAMETER["Latitude of natural origin",42.8333333333333,
> > #> ANGLEUNIT["degree",0.0174532925199433],
> > #> ID["EPSG",8801]],
> > #> PARAMETER["Longitude of natural origin",-70.1666666666667,
> > #> ANGLEUNIT["degree",0.0174532925199433],
> > #> ID["EPSG",8802]],
> > #> PARAMETER["Scale factor at natural origin",0.999966666666667,
> > #> SCALEUNIT["unity",1],
> > #> ID["EPSG",8805]],
> > #> PARAMETER["False easting",900000,
> > #> LENGTHUNIT["metre",1],
> > #> ID["EPSG",8806]],
> > #> PARAMETER["False northing",0,
> > #> LENGTHUNIT["metre",1],
> > #> ID["EPSG",8807]]],
> > #> CS[Cartesian,2],
> > #> AXIS["easting",east,
> > #> ORDER[1],
> > #> LENGTHUNIT["metre",1,
> > #> ID["EPSG",9001]]],
> > #> AXIS["northing",north,
> > #> ORDER[2],
> > #> LENGTHUNIT["metre",1,
> > #> ID["EPSG",9001]]]]
> >
> > In the spirit of not leaving things to the last minute (that's never
> > happened before!), what are the current options for converting proj
> > strings to WKT that don't use rgdal?
> >
> > Cheers and thanks,
> > Ben
> >
> > --
> > Ben Tupper (he/him)
> > Bigelow Laboratory for Ocean Science
> > East Boothbay, Maine
> > http://www.bigelow.org/
> > https://eco.bigelow.org
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
>
>
> --
>
>
>
> Have a nice day!
--
Ben Tupper (he/him)
Bigelow Laboratory for Ocean Science
East Boothbay, Maine
http://www.bigelow.org/
https://eco.bigelow.org
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic