Properties of spatial objects

The following code makes use of two packages: - the sf package, which is available from - the units package, which is available from To run the code of this notebook you can install the packages by install.packages(c("sf","units")). However, they are already installed in the container on which this example is run.

Linking to GEOS 3.7.1, GDAL 2.4.0, PROJ 5.2.0

The files “south-america-1990.RData” and “three-countries.RData” were created in a previous example.


8.472314e+12 [m^2]

in_km2 <- function(x) units::set_units(x,"km^2")
8472314 [km^2]

Units: [km^2]
 [1]  210585.6  144986.2  910860.6 2780991.8 1086612.6 8472314.3  744390.5
 [8]  255309.8  398803.1 1290857.6  177861.7 1135173.0

Units: [km^2]
   Guyana  Suriname Venezuela Argentina   Bolivia    Brazil     Chile   Ecuador
 210585.6  144986.2  910860.6 2780991.8 1086612.6 8472314.3  744390.5  255309.8
 Paraguay      Peru   Uruguay  Colombia
 398803.1 1290857.6  177861.7 1135173.0

Units: [m]
[1,] 3663768

Units: [m]
[1,] 2496612

# This takes a while, because R needs to figure out which points of the borders are the closest to one another
Units: [m]
[1,] 1468577

in_km <- function(x) units::set_units(x,"km")
Units: [km]
[1,] 3663.768

Units: [km]
         [,1]     [,2]     [,3]
[1,]    0.000 3014.942 3663.768
[2,] 3014.942    0.000 4232.052
[3,] 3663.768 4232.052    0.000

Downloadable R script and interactive version


The link with the “jupyterhub” icon directs you to an interactive Jupyter1 notebook, which runs inside a Docker container2. There are two variants of the interative notebook. One shuts down after 60 seconds and does not require a sign it. The other requires sign in using your ORCID3 credentials, yet shuts down only after 24 hours. (There is no guarantee that such a container persists that long, it may be shut down earlier for maintenance purposes.) After shutdown all data within the container will be reset, i.e. all files created by the user will be deleted.4

Above you see a rendered version of the Jupyter notebook.5


For more information about Jupyter see The Jupyter notebooks make use of the IRKernel package.


For more information about Docker see The container images were created with repo2docker, while containers are run with docker spawner.


ORCID is a free service for the authentication of researchers. It also allows to showcase publications and contributions to the academic community such as peer review.. See for more information.


The Jupyter notebooks come with NO WARRANTY whatsoever. They are provided for educational and illustrative purposes only. Do not use them for production work.


The notebook is rendered with the help of the nbsphinx extension.