HW12 DFT/Continuous Fourier Transform Relationship: Difference between revisions
(New page: The Question to answer here is: What is the relationship between the continuous Fourier Transform, and the discrete one? In words, you may describe the Discrete Fourier Transform (DFT) as...) |
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In words, you may describe the Discrete Fourier Transform (DFT) as a sampled Continuous Fourier Transform. The Discrete represents a finite amount of points |
In words, you may describe the Discrete Fourier Transform (DFT) as a sampled Continuous Fourier Transform. The Discrete represents a finite amount of points |
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on the continuous transform - enough so that you can reconstruct the signal to the correct amount of accuracy that you need, and prevent aliasing (see HW #11) |
on the continuous transform - enough so that you can reconstruct the signal to the correct amount of accuracy that you need, and prevent aliasing (see HW #11) |
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So why would you make a Discrete Fourier Transform? Why not just keep all the information you had in the first place with the continuous? Well, you could, you'd just |
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need an infinite amount of memory on your computer to store the infinite amount of points on the continuous waveform. And that would leave no room for your precious Mp3's and movie files. You wouldn't want that, would you? |
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But, if you're like me, this probably isn't enough description or motivation to truly understand the relationship between DFT's and CFT's. You want pictures, loud and clear. Here they are: |
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Revision as of 11:11, 30 November 2007
The Question to answer here is: What is the relationship between the continuous Fourier Transform, and the discrete one?
In words, you may describe the Discrete Fourier Transform (DFT) as a sampled Continuous Fourier Transform. The Discrete represents a finite amount of points on the continuous transform - enough so that you can reconstruct the signal to the correct amount of accuracy that you need, and prevent aliasing (see HW #11)
So why would you make a Discrete Fourier Transform? Why not just keep all the information you had in the first place with the continuous? Well, you could, you'd just need an infinite amount of memory on your computer to store the infinite amount of points on the continuous waveform. And that would leave no room for your precious Mp3's and movie files. You wouldn't want that, would you?
But, if you're like me, this probably isn't enough description or motivation to truly understand the relationship between DFT's and CFT's. You want pictures, loud and clear. Here they are: