Calculate Absolute Value in Python

For example, the absolute value of -2 is 2, and 2 is simply 2. In this article, we will explore how to calculate the absolute value of a number in Python.

Calculating Absolute Value in Python

The following methods can be efficiently used to calculate the absolute value of a number.

• Using User-Defined Function (Brute Method)
• Using abs() function
• Using math.fabs() function

Using User-Defined Function (Brute Method)

The following are steps for creating a function that will calculate the absolute value. This is a brute force approach (The brute method is a problem-solving approach that we will use to try all possible solutions for this).

• Create a function that returns the absolute value of the number passed to it as an argument.
• Use the if conditional statement to check whether the number is less than 0.
• Return the negative of the value if the condition is true i.e -(-) value becomes plus(+) which is the absolute value.
• Return the number passed if it is a positive number directly

Example 

The following example is calculating absolute value using a user-defined function.

# creating a function that returns the absolute value
def getAbsoluteValue(value):
   if(value<0):
      return -value
   return value
print("Absolute value of 5 = ", getAbsoluteValue(5))

# calling the getAbsoluteValue() function by passing some random negative number
print("Absolute value of -5 = ", getAbsoluteValue(-5))

Output

Absolute value of 5 =  5
Absolute value of -5 =  5

Using abs() function

The abs() function is a Python built-in function used to find the absolute value of a number. It is a simple way to calculate absolute value.

Example

The following program returns the absolute values of integers using the abs() function.

# input numbers(integers)
num_1 = 4
num_2 = -6
num_3 = 0
num_4 = -875
# calculating absolute values of input integers
print("absolute value of 4 = ", abs(num_1))
print("absolute value of -6 = ", abs(num_2))
print("absolute value of 0 = ", abs(num_3))
print("absolute value of -875 = ", abs(num_4))

Output

absolute value of 4 =  4
absolute value of -6 =  6
absolute value of 0 =  0
absolute value of -875 =  875

Using math.fabs() function

Python has the math.fabs() function in addition to the standard abs() function. Similar to the abs(), this function also accepts a single parameter representing an integer value and returns the absolute value of the given value as a floating-point value.

Example

The following program prints the absolute values of complex numbers using math.fabs() function.

# importing math module
import math
# input numbers
num_1 = 4
num_2 = -6.5
num_3 = -5
num_4 = -8
# calculating absolute values of input numbers as floating-point numbers
print("absolute value of 4 = ", math.fabs(num_1))
print("absolute value of -6.5 = ", math.fabs(num_2))
print("absolute value of -5 = ", math.fabs(num_3))
print("absolute value of -8.65 = ", math.fabs(num_4))

Output

absolute value of 4 = 4.0
absolute value of -6.5 = 6.5
absolute value of -5 = 5.0
absolute value of -8.65 = 8.0

Calculating the Absolute Value of Complex Numbers

We can also calculate the absolute value of Complex Numbers using the abs() function (we just need to pass a complex number as a parameter to this function).

A complex number is made up of both real and imaginary numbers. An imaginary number is one that is expressed in terms of the square root of a negative number.

They are typically stated in terms of value, which is the square root of -1. For example, ?6+?49 is a complex number where 6 is the real part and 49 is the imaginary part.

Example

In the following program, we are calculating the absolute values of complex numbers using the abs() function -

# input complex numbers
num_1 = 4+5j
num_2 = 2-3j
num_3 = -3-4j
# calculating absolute values of input complex numbers
print("absolute value of 4+5j = ", abs(num_1))
print("absolute value of 2-3j = ", abs(num_2))
print("absolute value of -3-4j = ", abs(num_3))

Output

absolute value of 4+5j = 6.4031242374328485
absolute value of 2-3j = 3.605551275463989
absolute value of -3-4j = 5.0