Abs
Function 
Abs(value)

Abs is included by default in each file as part of the Math library.
See also:
Use
The Abs() function returns the absolute value of a given number.
It will also return the "absolute value" of a given complex number (also called modulus). I.e. Abs(ai + b) = Sqrt(a^2 + b^2).
Examples
Abs(3.2 ft) = 3.2 ft
Abs(3i + 2) = 3.606