The Fourier Transform and Convolution Integrals

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  • Опубліковано 9 лют 2025
  • This video describes how the Fourier Transform maps the convolution integral of two functions to the product of their respective Fourier Transforms.
    Book Website: databookuw.com
    Book PDF: databookuw.com/...
    These lectures follow Chapter 2 from:
    "Data-Driven Science and Engineering: Machine Learning, Dynamical Systems, and Control" by Brunton and Kutz
    Amazon: www.amazon.com...
    Brunton Website: eigensteve.com
    This video was produced at the University of Washington

КОМЕНТАРІ • 59

  • @invinity3982
    @invinity3982 4 роки тому +34

    your in-depth explanation of complex concepts is phenomenal. thank you

    • @samernoureddine
      @samernoureddine 3 роки тому +8

      He does a pretty good job with real concepts too

  • @kummer45
    @kummer45 4 роки тому +7

    Subscribed. Took me one second to reason why.
    This man describes all the details in an exhaustive manner. This is exactly what many students are searching for. I can't imagine Lebesgue Integration at this level of detail. Even thinking about makes me cry of happiness. . There are many Doctors like him doing an outstanding job.
    And this was recommended as a random video.....

  • @趙嘉俊
    @趙嘉俊 11 місяців тому +3

    I'm really appreciate this video that professor made.It's helps me understanding this concept and helps me to accomplish my assignment, sorry for my bad english, thank you.

  • @karthickpn450
    @karthickpn450 4 роки тому +15

    Steve, Big fan of your lectures.

  • @erickappel4120
    @erickappel4120 9 місяців тому

    By far the best math lecturor i've ever experienced!

  • @supervince110
    @supervince110 2 роки тому

    Holy moly I've never found math so satisfying

  • @andrewgibson7797
    @andrewgibson7797 4 роки тому +60

    Hahaha. "Rather convoluted expression." I see what you did there.

  • @quantabot1165
    @quantabot1165 4 роки тому

    Its a liiitle bit convoluted . Smooth explanation, I havent done convolution integrals yet but i understood this

  • @udishsharma7861
    @udishsharma7861 3 місяці тому

    That's gorgeous man. Simple and nice

  • @AbhayaParthy
    @AbhayaParthy 4 роки тому +1

    Great video! Thanks Steve. I've learnt so much from your lectures.

  • @vivekvaghela2274
    @vivekvaghela2274 3 місяці тому +1

    Finally someone explained mathematically everything.

  • @taquilo
    @taquilo 2 роки тому

    I love this. I’m giving a crash course of DFT to my younger colleague, where I’m fuzzy on some theorem derivations.

    • @christopherneufelt8971
      @christopherneufelt8971 2 роки тому

      Is he still alive? Did you loose hair? Is still with Jenny or she separated him when she discovered some Fourier Convolutions on this desk?
      (Just some humor).

  • @thesila2000
    @thesila2000 3 роки тому

    i love u just survived my breakdown thank you seriously thank you

  • @br-rk5th
    @br-rk5th 4 роки тому +4

    Also, something else that I think needs to be addressed is the way that EVERYONE describes the difference between correlation and convolution. In the time domain, one of the functions is time reversed for convolution. But, and this is a big BUT, in the frequency domain it is when we are performing a cross-correlation that one of the DFTs is conjugated (equivalent to time reversal in the time domain). It took me a long time to sort this inherent ambiguity out. This ambiguity needs to be recognized. To assume that everyone realizes this is a big mistake.

  • @abcd1111223
    @abcd1111223 4 роки тому +2

    Thank u for ur clear explanation!

  • @ahmetenesbozcal2627
    @ahmetenesbozcal2627 2 роки тому +1

    Great series on FT's and FS's but It would be awesome to include dirac delta function in this lecture series

  • @SDen-mp4yc
    @SDen-mp4yc Рік тому

    Great video! Thanks.

  • @СерёжаСметанкин
    @СерёжаСметанкин 4 роки тому

    На часах 2 часа ночи, но я не могу оторваться. Круто!

  • @alfonsoortizavila4373
    @alfonsoortizavila4373 3 роки тому +2

    6:22, it is called Fubini's theorem :)

  • @jackzheninghuang891
    @jackzheninghuang891 4 роки тому

    saved my life! Thanks

  • @ML2011ML
    @ML2011ML 4 роки тому

    Fantastic representation!

  • @kaivinchen6042
    @kaivinchen6042 2 роки тому

    you saved my homework

  • @delendaanouar7180
    @delendaanouar7180 4 роки тому +4

    Great one, i want to thank you for your work. And i have also a request : can you make for us some videos about the following topics: Fast fourrier transforme (FFT) and the integrator operation. Thank you in advance.

    • @Eigensteve
      @Eigensteve  4 роки тому +6

      Thanks -- Yep, the FFT is coming soon!

  • @debajyotisg
    @debajyotisg Місяць тому

    4:41 "This is where it gets a little bit convoluted". Hah, quite topical!

  • @pritamroy3766
    @pritamroy3766 2 роки тому +1

    @SteveBrunton Hallow, professor Steve. A wonderful vide series with precise and definite explanation. First of all, thank you and your team. Now coming to my question and that is why do we need convolution ? We had function multiplication operation before but even then why we had to invent Convolution, what's the advantage and purpose of convolution ?

  • @michaelzap8528
    @michaelzap8528 Місяць тому

    Excellent

  • @p_square
    @p_square 4 роки тому

    At approx. 5:37, you said that you are going to multiply e^-i(omega)y with e^i(omega)x and you took i(omega) common for both the terms. But I think that you can't take -ve and +ve positive common because they are opposite. Or, what I think is that when you took i(omega) common, your final expression came out to be e^i(omega)(x - y) so you are correct. Please correct me If I am wrong

    • @sayanjitb
      @sayanjitb 4 роки тому

      yes, you are absolutely wrong and seem a bit confused. by algebraic property of exponential, one can add their exponents [e^a * e^b = e^(a+b) ; a,b belongs to R or C]

    • @p_square
      @p_square 4 роки тому

      @@sayanjitb I also thought the same but I got a bit confused and got the answer wrong. Thanks for correcting me

  • @sayanjitb
    @sayanjitb 4 роки тому

    Thank you so much for this embellished presentation. I got a doubt, what is the diffusion kernel, anyway?

  • @pranavsawant1439
    @pranavsawant1439 4 роки тому

    Amazing, thanks a lot!

  • @Pvt.N00B
    @Pvt.N00B 3 роки тому

    Great vid

  • @elsurexiste
    @elsurexiste 4 дні тому

    At 4:37
    Steve- This is where it gets a little bit convoluted...
    My poor self- I thought convolutions were the topic from the start 😥

  • @TheLeontheking
    @TheLeontheking Рік тому

    Massively simplify this "convoluted" expression :D

  • @preethamkumar4319
    @preethamkumar4319 2 роки тому

    Where does one use this property in physical applications?

  • @nullspace209
    @nullspace209 Рік тому

    There is a LOT to be said about the commutative property of the integrals. But I am sure simple minded physicists don't mind.

  • @finnjake6174
    @finnjake6174 4 роки тому

    love this

  • @br-rk5th
    @br-rk5th 4 роки тому

    With convolution in the time domain, we have to time reverse one of the functions before we do the convolution. When we do the convolution in the frequency domain(multiplication in frequency domain) do we have to time reverse one of the functions before we take its fourier transform? If not, why not?

    • @demr04
      @demr04 Рік тому

      No, because the time reversing appears naturally in the inverse transform.

  • @sebastianrada4107
    @sebastianrada4107 Рік тому

    "That is a little bit convoluted" hahahaha

  • @miqueasgamero7270
    @miqueasgamero7270 4 роки тому

    Wait, this guy is writing upside down? Pretty useful video btw

  • @br-rk5th
    @br-rk5th 4 роки тому

    It is not intuitively obvious to me that the in the formula for convolution ( sum over k (f(t)*g(t-k) ) that g(t-k) implies that it is time reversed. That is not obvious. What part of the formula for convolution (in the time domain) implies that one of the functions is reversed in time?

  • @rymsharman
    @rymsharman 4 роки тому

    The aesthetics in this video are crazy good but a bit unsettling lol

    • @rymsharman
      @rymsharman 4 роки тому +1

      I only want to be taught by a floating head and arms on a black background in 4K from now on.

  • @bobspianosbffl
    @bobspianosbffl 4 роки тому +6

    K-see
    Bless you
    K-see
    Bless you again

  • @alexeyl22
    @alexeyl22 4 роки тому

    Yes, this is it ))

  • @ugaugabugaduga
    @ugaugabugaduga Рік тому

    Is he writing backwards?

  • @erickgomez7775
    @erickgomez7775 Рік тому

    "My red integral" I guess Steve might be color blind, or I am color blind

  • @mathadventuress
    @mathadventuress 2 роки тому

    I thought it was 1/sqrt(2pi)?
    That’s what my professor taught us

  • @mohammadabdulla8601
    @mohammadabdulla8601 2 роки тому

    I like your videos but this is definitely not a rigorous mathematical setting for the problem.
    Engineers would like it but mathematicians will doubt alot of assumptions you already did in the proof.

  • @mogomotsiseiphemo1681
    @mogomotsiseiphemo1681 Рік тому

    I am not convinced!

  • @Seanovis
    @Seanovis Рік тому

    Kuh-sey might be the worst variable

  • @MathStringInputOutpu
    @MathStringInputOutpu 3 роки тому

    Who is this guy, why can he write in mirror like nobody's business?