Fourier Transform of a signal for which no function exists

Click For Summary
SUMMARY

The discussion focuses on applying the Discrete Fourier Transform (DFT) to a set of floating-point signal readings sampled every 4 milliseconds. The user seeks guidance on transforming these values into the frequency domain without a known function. It is established that utilizing a DFT is appropriate for this scenario, and the Fast Fourier Transform (FFT) is highlighted as an efficient algorithm for calculating the DFT, although they are not synonymous. Resources on digital signal processing are recommended for further understanding.

PREREQUISITES
  • Understanding of Discrete Fourier Transform (DFT)
  • Familiarity with Fast Fourier Transform (FFT) algorithms
  • Basic knowledge of digital signal processing concepts
  • Ability to work with floating-point data types
NEXT STEPS
  • Research the implementation of DFT using Python libraries such as NumPy
  • Explore the differences between DFT and FFT in detail
  • Study digital signal processing textbooks for foundational concepts
  • Learn about windowing techniques to improve frequency analysis
USEFUL FOR

This discussion is beneficial for signal processing engineers, data analysts, and anyone involved in analyzing time-series data using Fourier Transform techniques.

Gavin Harper
Messages
16
Reaction score
0
I have the readings from a signal in a file (floating point values) that I wish to apply the Fourier Transform to.

The samples (mV) were taken every 4 milliseconds and I wish to transform them into the frequency domain.

How would I apply the FT to a set of values without knowing any function that can describe even a discrete sample of it?

Thank you to anyone who can offer any insight!
 
Physics news on Phys.org
Use a digital Fourier transform (DFT) instead of the continuous Fourier transform defined using an integral. You can get he details from textbooks or websites on digital signal processing.

The term "FFT" (Fast Fourier transform) is often used as another name for "DFT", but that is not quite accurate. The FFT algorithm is one of several ways to calculate a DFT (and usually the quickest way), not the DFT itself.
 
Thank you!
 

Similar threads

Undergrad Peak of Analytical Fourier Transform
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad The domain of the Fourier transform
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Fourier transform, same frequencies, different amplitudes
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad What Causes Repetition in Fourier Transforms of Audio and Visual Data?
  • · Replies 12 ·
Replies
12
Views
3K
Undergrad The Relationship Between Angular and Cyclic Frequency in Fourier Transform
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Calculation of Fourier Transform Derivative d/dw (F{x(t)})=d/dw(X(w))
  • · Replies 3 ·
Replies
3
Views
11K
Graduate Fourier Transform: Nonperiodic vs Periodic Signals
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Ambiguous Results for two Fourier transform techniques
  • · Replies 7 ·
Replies
7
Views
3K
Graduate Memory issues in numerical integration of oscillatory function
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Fourier Transform and Hilber transform, properties
  • · Replies 4 ·
Replies
4
Views
1K