Python math.ldexp() Method

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The Python math.ldexp() method is used to calculate the value of a number "x" multiplied by 2ⁱ, where "x" is the significand (also known as mantissa) and "i" is the exponent.

For example, if you have a significand "x = 0.75" and an exponent "i = 3", then math.ldexp(0.75, 3) will return 0.75 × 2³ = 6.0.

Note: To use this function, you need to import math module.

Syntax

Following is the basic syntax of the Python math.ldexp() method −

math.ldexp(x, i)

Parameters

This method accepts the following parameters −

• x − It is the significand, which is a real number between 0.5 (inclusive) and 1.0 (exclusive).

• i − It is the exponent, which is an integer representing the power of 2.

Return Value

The method returns a float, which is the result of x × 2^exp.

Example 1

In the following example, we are calculating the ldexp of a number by raising it to a positive exponent −

import math
result = math.ldexp(0.75, 3)
print("The result obtained is:",result)         

Output

The output obtained is as follows −

The result obtained is: 6.0

Example 2

Here, we are calculating the ldexp of a number by raising it to a negative exponent −

import math
result = math.ldexp(1.5, -2)
print("The result obtained is:",result)  

Output

Following is the output of the above code −

The result obtained is: 0.375

Example 3

Now, we are calculating the ldexp of a number using "0" as the significand −

import math
result = math.ldexp(0, 5)
print("The result is:",result)  

Output

We get the output as shown below −

The result obtained is: 0.0

Example 4

In this example, we use variables "significand" and "exponent" to store the values "1.25" and "-3" respectively. We then calculate the ldexp −

import math
significand = 1.25
exponent = -3
result = math.ldexp(significand, exponent)
print("The result obtained is:",result)  

Output

The result produced is as shown below −

The result obtained is: 0.15625