install_conversion_constant {units} | R Documentation |
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).
install_conversion_constant(from, to, const) install_conversion_offset(from, to, const)
from |
String for the symbol of the unit being converted from. |
to |
String for the symbol of the unit being converted to. One of |
const |
The constant α in the conversion. |
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.
install_symbolic_unit
, remove_symbolic_unit
# 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