separateUnits

Separate units from expression

Syntax

[Data,Units] = separateUnits(expr)

Data = separateUnits(expr)

Description

[Data,Units] = separateUnits(expr) returns the units of the symbolic expression expr in Units and the rest of expr in Data.

Data = separateUnits(expr) removes symbolic units from expr and then returns the rest.

Examples

Separate Units and Expression

Separate the units from the expression 10*t*u.m/u.s, where u = symunit, by providing two output arguments for separateUnits.

u = symunit;
syms t
speed = 10*t*u.m/u.s;
[Data,Units] = separateUnits(speed)

Data =
10*t
Units =
1*([m]/[s])

Return only the expression with the units removed by providing one output argument.

Data = separateUnits(speed)

Data =
10*t

Separate Incompatible Units

When the expression has incompatible units, separateUnits errors. Units are incompatible when they do not have the same dimensions, such as length or time.

Separate the units from 2*u.m + 3*u.s, where u = symunit. The separateUnits function throws an error. Instead, to list the units in the input, use findUnits.

u = symunit;
[Data,Units] = separateUnits(2*u.m + 3*u.s)

Error using separateUnits (line 52)
Argument has incompatible units.

Separate Inconsistent Units

When the input has inconsistent units that can be converted to the same unit, then separateUnits performs the conversion and returns the separated result. Units are inconsistent when they cannot be converted to each other with a conversion factor of 1

Separate the units from 2*u.m + 30*u.cm. Even though the units differ, separateUnits converts them to the same unit and returns the separated result.

u = symunit;
[Data,Units] = separateUnits(2*u.m + 30*u.cm)

Data =
230
Units =
[cm]

Input Arguments

expr — Input

number | vector | matrix | multidimensional array | symbolic number | symbolic variable | symbolic vector | symbolic matrix | symbolic multidimensional array | symbolic function | symbolic expression

Input, returned as a number, vector, matrix or multidimensional array, or a symbolic number, variable, vector, matrix, multidimensional array, function, or expression.

Output Arguments

Data — Expression after removing units

number | vector | matrix | multidimensional array | symbolic number | symbolic variable | symbolic vector | symbolic matrix | symbolic equation | symbolic multidimensional array | symbolic function | symbolic expression

Expression after removing units, returned as a number, vector, matrix or multidimensional array, or a symbolic number, variable, vector, matrix, equation, multidimensional array, function, or expression.

Units — Units from input

symbolic units

Units from input, specified as symbolic units.