R: Install a conversion constant or offset between user-defined...

install_conversion_constant {units}

R Documentation

Install a conversion constant or offset 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 (constant) or y = α + x (offset).

Usage

install_conversion_constant(from, to, const)

install_conversion_offset(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. One of `from` and `to` must be an existing unit name.
`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 multiplying by a constant, or adding a constant.

Examples


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

install_conversion_offset("meter", "newmeter", 1)
m = set_units(1:3, meter)
n = set_units(1:3, newmeter)
m + n
n + m