The discrete fourier transform

In summary, the given 8-point data set was transformed with a DFT and the resulting array has values 1, 2, 3, 4, 5, 6, 7, 8. When performing a discrete Fourier transform on a real data set, the resulting array will always have complex values because of a property of the real DFT. This property states that the kth element of the output is the complex conjugate of the (N-k)th element, assuming the elements run from 0 to N-1. This can be easily proven using the DFT equation.
  • #1
zak8000
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Homework Statement


A 8-point data set is transformed with a DFT and the resulting array has values
1,2,3,4,5,6,7,8

was the data set real or complex? why?


Homework Equations





The Attempt at a Solution


kind of confused with this question all i know is the discrete Fourier transform converts a sequence into another. i did i previous question by performing the discrete Fourier transform on a signal which was sampled over a frequency but i don't understand this question.
 
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  • #2
Have you learned any properties of the real DFT? One property is that the kth element of the output is the complex conjugate of the (N-k)th element, assuming the elements run from 0 to N-1. It's not an immediately obvious property, but you can easily prove it using the DFT equation.
 

What is the discrete Fourier transform?

The discrete Fourier transform (DFT) is a mathematical algorithm used to analyze and decompose a finite sequence of data points into its constituent frequency components. It is commonly used in signal processing and data analysis applications.

How does the discrete Fourier transform work?

The DFT works by taking a finite sequence of data points and representing it as a combination of complex sine and cosine waves of different frequencies and amplitudes. This allows for the identification of the different frequency components present in the original data sequence.

What is the difference between the discrete Fourier transform and the continuous Fourier transform?

The discrete Fourier transform is used for analyzing a finite sequence of data points, while the continuous Fourier transform is used for analyzing continuous functions. The DFT operates on discrete data points, while the continuous Fourier transform operates on an infinite number of data points. In practice, the DFT is often used to approximate the continuous Fourier transform.

What are some applications of the discrete Fourier transform?

The DFT has a wide range of applications in various fields, including signal processing, data compression, image processing, and speech recognition. It is also used in solving differential equations and solving optimization problems in engineering and physics.

What are some limitations of the discrete Fourier transform?

The DFT has a fixed number of frequency components, meaning it may not accurately represent signals with rapidly changing frequencies. It is also affected by noise and artifacts in the data, which can lead to inaccuracies in the frequency analysis. Additionally, the DFT requires a significant amount of computational power and time for larger data sets.

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