Cite this package as Edzer Pebesma, Thomas Mailund and James Hiebert, 2016. Measurement Units in R. The R Journal, 8 (2), 486--494. The citation is found here. The units vignette is derived from this manuscript, and is kept up to date with the package.
Package units provides
measurement units for R vectors: conversion, derivation, simplification and error checking:
library(units)
(spd1 = set_units(1:5, m/s))
# Units: m/s
# [1] 1 2 3 4 5
(spd2 = set_units(1:5, km/h))
# Units: km/h
# [1] 1 2 3 4 5
spd1 + spd2 # automatic conversion
# Units: m/s
# [1] 1.277778 2.555556 3.833333 5.111111 6.388889
spd1 * spd2 # unit derivation
# Units: km*m/h/s
# [1] 1 4 9 16 25
spd1 * set_units(10, s) # unit simplification
# Units: m
# [1] 10 20 30 40 50
spd1 + set_units(10, s) # error checking
# cannot convert s into m/s
- blog posts: first, second, third
- package vignette
- The R Journal publication, which has been updated to recent package developments
- the udunits2 R package github page
- the UNIDATA udunits2 library at github
When installing the udunits2 R package fails due to a missing
udunits2 system library, either install it binary e.g. by
sudo apt-get install libudunits2-dev
or install from source by downloading udunits-2.2.20.tar.gz from
ftp://ftp.unidata.ucar.edu/pub/udunits/, and executing the
following commands in the download directory:
tar zxf udunits-2.2.20.tar.gz
cd ./udunits-2.2.20/
./configure
make
sudo make install
sudo ldconfig
if that went well, assuming you installed by default in /usr/local/, add
export UDUNITS2_XML_PATH="/usr/local/share/udunits/udunits2.xml"
to your ~/.bashrc file, start a new shell to activate this environment variable, and try installing R package udunits2 once more. When launching rstudio from unity, you may have to load udunits2 explicitly before using units, or set UDUNITS2_XML_PATH in a different way such that rstudio finds it.