What is cmath.phase(x) in Python?

The phase(x) function can be used to get the phase of a complex number. It accepts integer, float, and complex type argument value x.

The output of cmath.phase(x) is equivalent to math.atan2 (x.imag, x.real), and the range lies between [-π, π].

Note: The cmath module in Python has multiple methods used for mathematical operations on complex numbers, just like the math module for floating-point numbers.

Syntax

cmath.phase(x)

Parameters

This method accepts the following arguments:

  • x: The parameter value of which to find the phase.

Return Value

It returns float value, representing the phase of a complex number x.

Example

In this example, we discuss multiple types of argument values in cmath.phase(x).

  • Integer: It will return a phase.
  • Float: It will also return a phase.
  • Complex: If x.imag is negative, then it does not matter (+ve answer). But when x.real is negative, then the result will be the same but the sign will be of x.imag. See line 8.
import cmath # include library

# Integer argument

print(cmath.phase(-90))

# floating point value as argument

print(cmath.phase(90.9))

# complex number as an argument value

# Complex(x.real, x.imag)

print(cmath.phase(complex(-1.0, -1.0)))

print(cmath.phase(complex(-1.0, 0.0)))

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