african administrative boundaries
To make administrative boundary polygons for Africa easily accessible from R.
A part of the afrimapr project.
In early development, contact Andy South with questions.
There are various sources of administrative boundaries available on the web, and existing R packages for accessing them.
This package will improve access to boundaries for Africa.
It will start by giving access to African admin boundaries at all levels from gadm.org (probably the best current source of global admin boundaries).
As a first step I've saved all the full resolution gadm files (~ 88MB) in the package to save having to download them each time. Later we may choose to save just lower resolution versions. CRAN policy "As a general rule, neither data nor documentation should exceed 5MB ... Where a large amount of data is required (even after compression), consideration should be given to a separate data-only package which can be updated only rarely".
I'll develop interface functions that are intended to stay similar, what is happening behind may change.
Install the development version from GitHub using devtools.
# install.packages("devtools") # if not already installed
devtools::install_github("afrimapr/afriadmin")
library(afriadmin)
library(sf)
# with interactive map
sfken <- afriadmin("kenya",level='max', plot='mapview')
# static map
sfeth <- afriadmin("ethiopia",level='max', plot='sf')
afriadmin("Angola",level=2)
# todo move the readme to an Rmd to allow plots
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Single country maps. We want to target in-country use. People in Africa making maps of Africa. Maybe there will be a greater utility for tools that make it easy to make maps of a single country rather than of multiple countries ?
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low resolution boundaries just for display at country level
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higher resolution boundaries to allow zooming in. (e.g. what detail is needed in a polygon boundary file to be able to create zonal statistics for a raster file of a given cell size ?)