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How to extract frequency associated with fft values?

Learn, how to extract frequency associated with fft values in Python?
By Pranit Sharma Last updated : December 21, 2023

NumPy is an abbreviated form of Numerical Python. It is used for different types of scientific operations in python. Numpy is a vast library in python which is used for almost every kind of scientific or mathematical operation. It is itself an array which is a collection of various methods and functions for processing the arrays.

Extracting frequency associated with fft values

The numpy.fft.fft() computes the one-dimensional discrete Fourier Transform. This function computes the one-dimensional n-point discrete Fourier Transform (DFT) with the efficient Fast Fourier Transform (FFT) algorithm [CT].

We will use numpy.fft.fftfreq() which tells us the frequencies associated with the coefficients.

Let us understand with the help of an example,

Python code to extract frequency associated with fft values

# Import numpy
import numpy as np

# Creating a numpy array
arr = np.array([1,2,1,0,1,2,1,0])

# Display original array
print("Original array:\n",arr,"\n")

# Computing fft values
res = np.fft.fft(arr)

# Display fft values
print("fft values:\n",res,"\n")

# Calculating frequencies
fre = np.fft.fftfreq(len(arr))

# Display Result
print("Result:\n",fre)

Output

Example: How to extract frequency associated with fft values?