`unitConvert`

Converts a quantity to other units.

Category: Symbolic Computations in MATLAB > Units of Measurement

Syntax

y = unitConvert(x, u2)

Converts x to the unit or unit expression u2.

y = unitConvert(x, 'SI')

Converts x to SI units.

y = unitConvert(___, 'Temperature', mode)

With 'absolute', converts temperatures as readings, not as differences (default 'difference').

Description

The conversion multiplies the number by the ratio between the units, using exact rational factors, so 60 mi/h in km/h is a fraction instead of a rounded decimal. Use double on the numeric part to get a decimal.

Units of different dimensions cannot be converted into one another. Temperatures need care: 'difference' treats Celsius and K as scales of an interval, while 'absolute' includes the offset, so 100 Celsius is 212 Fahrenheit.

Input arguments

x: Symbolic quantity with units.
u2: Target unit, such as u.m, or a combination like u.km/u.h.
'Temperature': 'difference' (default) or 'absolute'.

Output arguments

y: Quantity expressed in the target units, as an exact symbolic value.

Example

Length, speed and temperature

u = symunit;
unitConvert(3*u.km, u.m)
unitConvert(5*u.m/u.s, u.km/u.h)
unitConvert(100*u.Celsius, u.Fahrenheit, 'Temperature', 'absolute')

Output

ans = 3000*[m]
ans = 18*([km]/[h])
ans = 212*[Fahrenheit]

Notes

In MatLivre a unit system name as target works for 'SI'; 'CGS' and 'US' are accepted but return the quantity in SI units. Converting between units of different dimensions does not raise an error and returns the quantity unchanged.

unitConvert