Principle value (of an argument)
The complex argument of a complex number z in the interval [0, 2π) is called the principle value. The interval (−π, π] can also be taken.
Explanation
You write a complex number z in phasor notation as
Where |z| is a positive real number, and you call this the modulus of z. The complex argument θ (theta) is a real number that specifies the angle with the real x-axis.
Example 1
The principle value of angle θ is calculated with arg (z) as
via the rectangular coordinates (−1, −1) and (0, 1).