Hello, I would like to have the list of coordinates of the boundary (outline) of a continent (Africa). The "map" function from the "maps" package gives the coordinates for country outlines, but not the for the continents. Does anybody have an idea where I can find the data? Thank you! Cheers, Sohrab
How to get the coordinates (latitude/longitude) of a continent outline?
6 messages · Zivan Karaman, Sohrab Abbasnejad, Ben Tupper
Hi, There is a whole world of options (sorry for the lame pun!), but I would recommend checking out ROpenSci's rnaturalearth package https://ropensci.org/tutorials/rnaturalearth_tutorial/ <https://ropensci.org/tutorials/rnaturalearth_tutorial/> https://CRAN.R-project.org/package=rnaturalearth <https://cran.r-project.org/package=rnaturalearth> Ben
On Feb 2, 2019, at 8:36 AM, Sohrab Abbasnejad via R-sig-Geo <r-sig-geo at r-project.org> wrote: Hello, I would like to have the list of coordinates of the boundary (outline) of a continent (Africa). The "map" function from the "maps" package gives the coordinates for country outlines, but not the for the continents. Does anybody have an idea where I can find the data? Thank you! Cheers, Sohrab [[alternative HTML version deleted]]
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Ben Tupper Bigelow Laboratory for Ocean Sciences 60 Bigelow Drive, P.O. Box 380 East Boothbay, Maine 04544 http://www.bigelow.org Ecological Forecasting: https://eco.bigelow.org/
Hello Sohrab, You can start with country maps, and then merge them in a single polygon. For example, get the maps as a shape file from here http://www.maplibrary.org/library/stacks/Africa/Africa_SHP.zip, unzip this file and run the following R code library(sp) library(rgdal) library(rgeos) countries <- rgdal::readOGR(dsn = ".", layer = "Africa") sp::proj4string(countries) <- sp::CRS("+init=epsg:4326") a <- rgeos::gBuffer(countries, width = 0) # ignore the warnings sp::proj4string(a) <- sp::CRS("+init=epsg:4326") plot(a) # this produces quite a detailed map with islands, lakes, etc. # you can simplify it to suit your needs by tuning the tol argument b <- rgeos::gSimplify(a, tol = 0.1) plot(b) Cheers, Zivan Le sam. 2 f?vr. 2019 ? 14:36, Sohrab Abbasnejad via R-sig-Geo < r-sig-geo at r-project.org> a ?crit :
Hello,
I would like to have the list of coordinates of the boundary (outline) of
a continent (Africa). The "map" function from the "maps" package gives the
coordinates for country outlines, but not the for the continents.
Does anybody have an idea where I can find the data?
Thank you!
Cheers,
Sohrab
[[alternative HTML version deleted]]
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Dear Ben, Thank you for your reply. So far as I am aware, the rnaturalearth package provides information about countries within a continent, states within countries and "world" coastline (subsetting the coastline is not possible). Nevertheless, the package does not include maps/data of "continents". What I need is the coordinates of Africa's outline (as a single entity), not the coordinates of countries' outlines within Africa. Best, Sohrab
On ?Saturday?, ?February? ?2?, ?2019? ?03?:?38?:?25? ?PM? ?CET, Ben Tupper wrote:
Hi, There is a whole world of options (sorry for the lame pun!), but I would recommend checking out ROpenSci's rnaturalearth package https://ropensci.org/tutorials/rnaturalearth_tutorial/ https://CRAN.R-project.org/package=rnaturalearth Ben
On Feb 2, 2019, at 8:36 AM, Sohrab Abbasnejad via R-sig-Geo <r-sig-geo at r-project.org> wrote:
Hello, I would like to have the list of coordinates of the boundary (outline) of a continent (Africa). The "map" function from the "maps" package gives the coordinates for country outlines, but not the for the continents. Does anybody have an idea where I can find the data? Thank you! Cheers, Sohrab _______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo Ben Tupper Bigelow Laboratory for Ocean?Sciences 60 Bigelow Drive, P.O. Box 380 East Boothbay, Maine 04544 http://www.bigelow.org Ecological Forecasting: https://eco.bigelow.org/
Dear Zivan, Your solution did the job! Thank you very much! Best, Sohrab
On ?Saturday?, ?February? ?2?, ?2019? ?04?:?07?:?27? ?PM? ?CET, Zivan Karaman <zivan.karaman at gmail.com> wrote:
Hello Sohrab, You can start with country maps, and then merge them in a single polygon.For example, get the maps as a shape file from here http://www.maplibrary.org/library/stacks/Africa/Africa_SHP.zip, unzip this file and run the following R code library(sp)library(rgdal)library(rgeos)countries <- rgdal::readOGR(dsn = ".", layer = "Africa") sp::proj4string(countries) <- sp::CRS("+init=epsg:4326")a <- rgeos::gBuffer(countries, width = 0)# ignore the warningssp::proj4string(a) <- sp::CRS("+init=epsg:4326")plot(a)# this produces quite a detailed map with islands, lakes, etc.# you can simplify it to suit your needs by tuning the tol argumentb <- rgeos::gSimplify(a, tol = 0.1)plot(b) Cheers,Zivan Le?sam. 2 f?vr. 2019 ??14:36, Sohrab Abbasnejad via R-sig-Geo <r-sig-geo at r-project.org> a ?crit?: Hello, I would like to have the list of coordinates of the boundary (outline) of a continent (Africa). The "map" function from the "maps" package gives the coordinates for country outlines, but not the for the continents. Does anybody have an idea where I can find the data? Thank you! Cheers, Sohrab ? ? ? ? [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
Hi, Yes, I flubbed that. I had it in my head that this... https://www.naturalearthdata.com/downloads/110m-physical-vectors/110m-land/ <https://www.naturalearthdata.com/downloads/110m-physical-vectors/110m-land/> ... had Africa as a stand alone polygon, but that is not so. Sorry for the noise. Ben
On Feb 2, 2019, at 10:17 AM, Sohrab Abbasnejad <sohrab.abbasnejad at yahoo.com> wrote: Dear Ben, Thank you for your reply. So far as I am aware, the rnaturalearth package provides information about countries within a continent, states within countries and "world" coastline (subsetting the coastline is not possible). Nevertheless, the package does not include maps/data of "continents". What I need is the coordinates of Africa's outline (as a single entity), not the coordinates of countries' outlines within Africa. Best, Sohrab On ?Saturday?, ?February? ?2?, ?2019? ?03?:?38?:?25? ?PM? ?CET, Ben Tupper wrote: Hi, There is a whole world of options (sorry for the lame pun!), but I would recommend checking out ROpenSci's rnaturalearth package https://ropensci.org/tutorials/rnaturalearth_tutorial/ <https://ropensci.org/tutorials/rnaturalearth_tutorial/> https://CRAN.R-project.org/package=rnaturalearth <https://cran.r-project.org/package=rnaturalearth> Ben
On Feb 2, 2019, at 8:36 AM, Sohrab Abbasnejad via R-sig-Geo <r-sig-geo at r-project.org <mailto:r-sig-geo at r-project.org>> wrote: Hello, I would like to have the list of coordinates of the boundary (outline) of a continent (Africa). The "map" function from the "maps" package gives the coordinates for country outlines, but not the for the continents. Does anybody have an idea where I can find the data? Thank you! Cheers, Sohrab [[alternative HTML version deleted]]
_______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org <mailto:R-sig-Geo at r-project.org> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
Ben Tupper Bigelow Laboratory for Ocean Sciences 60 Bigelow Drive, P.O. Box 380 East Boothbay, Maine 04544 http://www.bigelow.org <http://www.bigelow.org/> Ecological Forecasting: https://eco.bigelow.org/ <https://eco.bigelow.org/>
Ben Tupper Bigelow Laboratory for Ocean Sciences 60 Bigelow Drive, P.O. Box 380 East Boothbay, Maine 04544 http://www.bigelow.org Ecological Forecasting: https://eco.bigelow.org/