Measurement Units for R

News

Cite this package as Edzer Pebesma, Thomas Mailund and James Hiebert, 2016. Measurement Units in R. The R Journal, 8 (2), 486--494.. The main units vignette derives from this manuscript and is kept up to date with the package development.

What it does

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

Installation

Install the release version from CRAN:

install.packages("units")

The installation of the development version from GitHub requires, e.g., the remotes package:

remotes::install_github("r-quantities/units")

If the installation fails due to a missing udunits2 system library, either install it e.g. on Ubuntu or Debian by

sudo apt-get install libudunits2-dev

on CentOS7 with

sudo yum install udunits2-devel

or on MacOS with

brew install udunits

or equivalent in your distribution. Alternatively, install it from the sources 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

Then, retry the installation of units.