install_conversion_constant {units}R Documentation

Install a function for conversion between user-defined units.

Description

Tells the units package how to convert between units that have a linear relationship, i.e. can be related on the form y = α x.

Usage

install_conversion_constant(from, to, const)

Arguments

from

String for the symbol of the unit being converted from.

to

String for the symbol of the unit being converted to.

const

The constant α in the conversion.

Details

This function handles the very common case where units are related through a linear function, that is, you can convert from one to the other as y = α x. Using this function, you specify that you can go from values of type from to values of type to by first multiplying a constant and then adding an offset. The function then automatically installs that conversion and the invers x = y/α.

For a more general conversion mechanism, see install_conversion_function.

See Also

install_conversion_function

Examples


apples <- 2 * make_unit("apple")
oranges <- 1 * make_unit("orange")
# one orange is worth two apples
install_conversion_constant("orange", "apple", 2)
apples + oranges
oranges + apples


[Package units version 0.4-5 Index]