newUnit

Define new unit

Description

example

newUnit(name,definition) defines the new unit name using the expression definition. The definition must be in terms of existing symbolic units. You cannot redefine a predefined unit or its alternate names.

Examples

Define New Unit and Rewrite Unit

Define the new unit speedOfLight as 3e8 meters per second.

u = symunit;
c = newUnit('speedOfLight',3e8*u.m/u.s)
c =
[speedOfLight]

Define the famous equation E = mc2 using the new unit.

syms mass
m = mass*u.kg;
E = m*c^2
E =
mass*[kg]*[speedOfLight]^2

Alternatively, you can specify the unit by using u.SpeedOfLight.

Rewrite E in terms of meters per second.

E = rewrite(E,u.m/u.s)
E =
90000000000000000*mass*(([kg]*[m]^2)/[s]^2)

Since the standard unit of energy is the Joule, rewrite E in terms of Joule.

E = rewrite(E,u.J)
E =
90000000000000000*mass*[J]

Input Arguments

collapse all

Name of the new unit, specified as a character vector or string. You cannot redefine a predefined unit or its aliases.

Definition of the new unit, specified as a symbolic expression of units. The new unit must be defined in terms of existing symbolic units. For example, newUnit('workday',8*u.hour) where u = symunit.

Introduced in R2017a