The Convolution of Two Functions | Definition & Properties

Поделиться
HTML-код
  • Опубликовано: 3 фев 2025

Комментарии • 187

  • @ejkitchen
    @ejkitchen 3 года назад +89

    As many others have stated, thank you for making this very easy to understand. It's fascinating how many bad profs there are out there attempting to teach this. If you think about it, it's not that hard but for some reason, many people struggle to explain this properly because they do not spend the time like you did to make it accessible. Again, thank you for doing this.

  • @vaibhavdlxit1050
    @vaibhavdlxit1050 2 года назад +35

    You turned convolution from a dreaded enemy to an important ally which springs up to rescue while performing inverse laplace of evil looking functions. You sir, are a hero.

  • @nice4hat
    @nice4hat 3 года назад +172

    I like your t-shirt haha

  • @bromarskiii
    @bromarskiii 4 года назад +36

    You just explained convolution 100 times better than my textbook and my professor! Thanks!!

  • @ricardobautista-garcia8492
    @ricardobautista-garcia8492 3 года назад +21

    Wonderfully explained. Time to do my final exam. Thank you once again.

  • @josiahkolar4209
    @josiahkolar4209 3 года назад +6

    This playlist and the ODE playlist have been getting me through this 5 week summer class

  • @RubALamp
    @RubALamp 4 года назад +2

    I hope you grow in popularity. Not that it should be needed, but I think many people would benefit from your insight. Thank you for your videos.

  • @sobhanboss3935
    @sobhanboss3935 4 года назад +8

    this came in clutch, you made it so simple while my professor made it super confusing so thank you Trefor

  • @migo77
    @migo77 4 года назад +5

    Starting from 10:06 when you starting evaluating the integral & on the second line, the last part should have read: -0.5*TAU*cost t, because your're integrating w.r.t. TAU. Anyways, thanks v. much for all your efforts. God bless!

  • @BentHestad
    @BentHestad 4 года назад +9

    A quite difficult (but so essential!) concept very well explained! Thanks!

  • @sarveshchandak
    @sarveshchandak 4 года назад +12

    You cleared up all my confusion. Thanks a lot. ❤️❤️❤️

    • @DrTrefor
      @DrTrefor  4 года назад +2

      You’re welcome 😊

  • @RanbirSingh-no3mc
    @RanbirSingh-no3mc 3 года назад +1

    Best video on RUclips till date

  • @NPCNo-xm2li
    @NPCNo-xm2li Год назад

    You are single-handedly carrying all my math related subjects throughout my degree.

  • @eric_welch
    @eric_welch 3 года назад +5

    Just got yourself a new sub :) thank you for the concise way you explain things

    • @DrTrefor
      @DrTrefor  3 года назад +3

      Thanks for subbing!

  • @jaydean5243
    @jaydean5243 4 года назад +8

    Dr Trefor, as usual excellent videos, If there are any math/engineering students that don't "Ace" their exams it is THERE fault...Great JOB !

  • @DrDerivative
    @DrDerivative 3 года назад +13

    if a = tau and b = t - tau, then how did you get b - a = 2tau - t? shouldnt it be t - 2tau?

  • @visualgebra
    @visualgebra 4 года назад

    You and Dr Peyam have best explanation of Convolution!

  • @ProfeARios
    @ProfeARios 9 месяцев назад

    Great video. Thank you for sharing. Regards from Panama 🇵🇦

  • @ConceptualCalculus
    @ConceptualCalculus 4 года назад +15

    Just yesterday I was searching for a vid on convolution for my ODE class. Today this new vid popped up in my feed. I'm using it to replace the one I found yesterday, I suppose I should watch this one first, but that's not really necessary. If it is a Trefor Bazett vid, it is good.

  • @zulhishamtan4308
    @zulhishamtan4308 3 года назад

    Dr. Trefor....
    First of all, I like your T-Shirt.
    Thank you very much for sharing the knowledge.

  • @PiyushPastor
    @PiyushPastor 3 года назад +4

    Wow. Only if the classes were this good.

  • @SHAHHUSSAIN
    @SHAHHUSSAIN 4 года назад +5

    As usual outstanding...❤❤👏👏

  • @farukdemirel903
    @farukdemirel903 3 года назад +1

    Great explanation! and also I liked the t-shirt..

  • @Ayrmodros
    @Ayrmodros 2 года назад

    Thanks so much. The example my teacher gived is so complicated and confusing. Your example helped me totally understand it.

  • @hectorgalva7495
    @hectorgalva7495 3 года назад +2

    So good, so far. Awesome!!!😄😄

  • @m7mdarwani964
    @m7mdarwani964 3 года назад +3

    Clear and concise.

  • @johanfrancis2001
    @johanfrancis2001 2 года назад +1

    Dr you really doing a good job...appreciate ur work.
    ..

  • @ase1362
    @ase1362 3 года назад +3

    You are of great help. Thanks

  • @codyfan1097
    @codyfan1097 2 года назад +2

    Your videos are so helpful doc ❤️🙏

  • @paulkanucawec9489
    @paulkanucawec9489 Год назад

    What a concise explantation? Thank you Dr.

  • @eggxecution
    @eggxecution Год назад +1

    at 10:00 I think you made a mistake in trigo identity, it should be (a-b) also (a+b) to prevent confusion. This identity is product to sum formula if I recall correctly

  • @fernandogallardo3477
    @fernandogallardo3477 3 года назад +2

    Good stuff for my signals and systems class.

  • @manrajmann4732
    @manrajmann4732 3 года назад +1

    love from India sir !

  • @beophobic9653
    @beophobic9653 5 месяцев назад

    Great explanations!

  • @williambenish1718
    @williambenish1718 Месяц назад

    This was very helpful.

  • @joaomattos9271
    @joaomattos9271 Год назад +2

    Thank you very much!!!!!

  • @RAMKUMAR-rh4um
    @RAMKUMAR-rh4um 8 месяцев назад

    Nice T shirt sir, covered all functions 😊

  • @hsotnicam
    @hsotnicam 4 года назад +5

    Little known fact: the verb for convolution is "to convolve," which means to roll something together. Although it absolutely also "convoluted" the two functions - meaning making something more difficult to understand, it is not what it intend to do :-D

  • @rmb706
    @rmb706 2 года назад +6

    Believe it or not, probability brought me here. I was looking for a more rigorous definition of a convolution. I never studied the Laplace transform. Interestingly enough, two nonnegative RVs that have the same Laplace transform have the same distribution.

  • @matteodare1706
    @matteodare1706 3 года назад +5

    this is what i was looking for! thank you for the amazing video.

  • @JohnAbreu17
    @JohnAbreu17 4 года назад +2

    Thank you for your great work. Probably missing a little comment about the Domain of *.

  • @sogol2261
    @sogol2261 2 года назад +1

    Great video. 👍👍👍

  • @JOAE23
    @JOAE23 8 месяцев назад

    Well explained. Thank you!

  • @BoZhaoengineering
    @BoZhaoengineering 4 года назад +16

    Professor Trefor your T shirt is fantastic. Can you please tell me where I can buy one?

    • @Tosti_bakker
      @Tosti_bakker 4 года назад +5

      Same haha, I was looking more at his shirt than listening to his explanation

  • @yuzou2008
    @yuzou2008 4 года назад +3

    I love ur T-Shirt!

  • @philcooper279
    @philcooper279 2 года назад +1

    Simply brilliant.

  • @TUCSKIRTHIKR
    @TUCSKIRTHIKR 3 года назад +7

    Everybody : let us revise for tomorrow's exam
    Me at 12.am :

  • @sergiopallas4567
    @sergiopallas4567 2 года назад

    I'm sure I can't be the only one with this question. Where can we get that t-shirt? As always great video, thanks for helping those in need!!

  • @procerpat9223
    @procerpat9223 2 года назад +1

    Nicely done

  • @muhammadfaizan2232
    @muhammadfaizan2232 3 года назад +1

    Clear and Great

  • @uchiha_kakashi6716
    @uchiha_kakashi6716 Год назад +2

    so what is the difference between multiplication and convolution

  • @kenny44871
    @kenny44871 4 года назад

    Great video as usual

  • @michaelholland5424
    @michaelholland5424 2 года назад +1

    very nice video.

  • @AS-bg9lg
    @AS-bg9lg Год назад

    Hello, thanks for the video, I appreciate it!
    Btw, where did you get your t-shirt from? I like it, haha.

  • @amroalatasi2415
    @amroalatasi2415 2 года назад

    That was very helpful Dr. Bazzet, thank you. Can you please send me the link of the shirt you’re wearing? It’s amazing.

  • @abang571
    @abang571 4 года назад +6

    Dr, in your example, how can you get (2T - t) instead of (t - 2T) ? Help me out 🥺😭

    • @edilmarlulab7079
      @edilmarlulab7079 4 года назад

      Use trigo. Identities
      from sin(T)sin(t-T)
      let A=T & B=t-T
      Then Subtract to get sinAsinB:
      cos(A-B) = cosAcosB + sinAsinB
      cos(A+B) = cosAcosB - sinAsinB
      cos(A-B) - cos(A+B) = 2sin(A)sin(B)
      sin(A)sin(B) = 1/2[cos(A-B) - cos(A+B)]
      Then Substitute: (A = T ; B = t-T)
      sin(T)sin(t-T) = 1/2{cos[(T) - (t - T)] - cos[(T) + (t - T)]}
      Then you get:
      sin(T)sin(t-T) = 1/2[cos(2T - t) - cos(t)]

    • @thejohncenafan100
      @thejohncenafan100 2 года назад

      Cos is an even function therfore cos(x) = cos(-x) for every x in R.

    • @eggxecution
      @eggxecution Год назад

      I know what you meant fam, I saw the mistake in the video too. If you check the trigo identity he posted at 10:00 its (b-a) it should be (a-b) you'll arrive at 2T-t

  • @master_zenrade
    @master_zenrade 3 года назад +2

    Whoah T shirt 👚 contains summary of one year of Mathematics.

  • @prashantjoshi5389
    @prashantjoshi5389 Год назад

    6:25 but why is L[f(t) * g(t)] = F(s) . G(s) ? Is there a different derivation for this property??

  • @sujanban686
    @sujanban686 7 месяцев назад

    I looked at your T-shirt more times than I used in the class.

  • @twillkickers
    @twillkickers 2 года назад

    At 4:00, how does dtau turn into negative du? Where did the t go?

  • @universalalgorithm3263
    @universalalgorithm3263 2 года назад +2

    Why do convolutions need to be so convoluted?

  • @thepie-phitalks07
    @thepie-phitalks07 2 года назад +1

    Please bring a video on generalized convolution ( reference t. M Apostol)

  • @chinnamuniyandi2023jrf
    @chinnamuniyandi2023jrf 4 месяца назад

    If limit has between negative infinity to t in the convolution formula instead of negative infinite to positive infinite, should we call LTI system? Please reply.

  • @stringsam
    @stringsam 4 года назад

    really well explained :)

  • @vicadegboye684
    @vicadegboye684 Год назад +1

    Where did you get that your shirt from? I love it. I was hoping to see it in your store. Would definitely buy it if you're selling it

    • @DrTrefor
      @DrTrefor  Год назад +1

      My wife actually gave it as a present years ago and I've never been able to find the exact one again!

    • @vicadegboye684
      @vicadegboye684 Год назад

      @@DrTrefor Oh no! 😭

  • @noureldinechaker131
    @noureldinechaker131 3 года назад +2

    spent more time looking at the shirt than actually paying attention XD

  • @gulsumsecilsermet8583
    @gulsumsecilsermet8583 8 месяцев назад

    Thank you for the explanation. There is just one thing which is bother me. Sometimes speak rate is very fast then it becomes slow suddenly. Sometimes I couldn't understand that I needed to slow the video and it can be distructor.

  • @raghuveerdani4046
    @raghuveerdani4046 Год назад

    How did the sign of integral change? I did not get that part. What of we are integrating from -inf to inf??

  • @tjk581
    @tjk581 4 года назад +3

    I don't know. The definition of convolution is integral from 0 to t, or from -inf to +inf? In different sources, it's defined differently. Can someone explain?

    • @DrTrefor
      @DrTrefor  4 года назад +5

      If f and g are zero for negative values, then they are the same and the int from negative infinity to infinity is the same as 0 to t

    • @tjk581
      @tjk581 4 года назад

      @@DrTrefor But for evaluating convolution of f(x)=g(x)=sin(x) you used integral form 0 to t , when sin(x) isn't 0 for negative x.

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 года назад +2

      @@tjk581 But the Laplace transform only cares about the values of f(x) for positive x, so you can define f piecewise so that it is sin(x) only for x > 0, giving the result in the video.

  • @theblitz1687
    @theblitz1687 Год назад

    this was great

  • @neptune8422
    @neptune8422 3 года назад +1

    I like your T shirt!

  • @deyardeyar8163
    @deyardeyar8163 3 года назад

    10:15 what happened to the tau in the interation

  • @MisterBinx
    @MisterBinx 3 года назад +1

    I need to solved this integral and it really confuses me. I don't understand that t-tau part being in the argument.

  • @j.o.5957
    @j.o.5957 3 года назад

    Although I might not understand much of this yet, I'm beginning to grasp how to do the calculations

  • @jacobanderson5693
    @jacobanderson5693 4 года назад +1

    Thanks so much.

  • @JuntaoChu
    @JuntaoChu 2 года назад

    May I know where can I buy your t-shirt? It's so cute! (That blue one with many common math functions. )

  • @kexinsaw7092
    @kexinsaw7092 2 года назад +1

    I like your shirt!

  • @ahmedesamamer
    @ahmedesamamer 3 года назад +1

    Where can l get that T shirt ?

  • @KhinThazin-nx8xd
    @KhinThazin-nx8xd 7 месяцев назад

    Thank you

  • @Acesushii
    @Acesushii 3 года назад

    what about differential property? time shift and fourier ? halpp ;u;

  • @asadshamsiev2462
    @asadshamsiev2462 3 года назад

    Thank you Marc Gasol

  • @SuperHovik
    @SuperHovik 2 года назад

    How did you get -(1/2)tcost?

  • @leixiao169
    @leixiao169 2 года назад

    Where can we buy the T-shirt you wear ☺️?

  • @nnamdiYT
    @nnamdiYT 2 года назад

    I heard another term called polynomial mutiplication used exchangable with the convulution.Are they the same or different?How do they relate?

  • @felixgomez5085
    @felixgomez5085 3 года назад +1

    Nice !

  • @x_ma_ryu_x
    @x_ma_ryu_x 3 года назад +1

    life saver

  • @liheather2367
    @liheather2367 3 года назад

    where did you get this Tshirt, professor?

  • @joesmith8288
    @joesmith8288 4 года назад +1

    6:20 Can we also say that this is an isomorphism?

    • @joesmith8288
      @joesmith8288 4 года назад

      @@DrTrefor Got it. Thank you!

  • @NimbusAbi
    @NimbusAbi 3 года назад +1

    where can i get this shirt?

  • @sergiomanzetti1021
    @sergiomanzetti1021 2 года назад

    Where can I get that t-shirt?

  • @josephhajj1570
    @josephhajj1570 4 года назад

    Oh thanks I'm taking electricity course and I'm using it very much

    • @josephhajj1570
      @josephhajj1570 4 года назад

      @@DrTrefor yeah of course it's almost all EM based on laplace transform for signals....

  • @blackspitit
    @blackspitit 3 года назад

    Hi, how is this related to a convolution in a Convolutional Neural Network?

  • @MachoMandem
    @MachoMandem 3 года назад

    I subbed for the shirt, stayed for the video

  • @superdahoho
    @superdahoho 4 года назад +4

    nice shirt btw, where can I get it?

    • @rtusiime
      @rtusiime 4 года назад

      I'm wondering the same thing

  • @MrMobi007
    @MrMobi007 3 года назад +1

    the only thing wrong with this video is we still don't know where to get the epic t-shirt.

  • @continnum_radhe-radhe
    @continnum_radhe-radhe 2 года назад +1

    🔥🔥🔥

  • @tesset8828
    @tesset8828 4 года назад +1

    your shirt but y is the indicator function on a dense set :)

  • @aoqu8349
    @aoqu8349 4 года назад

    How we get 2j-t, shouldnot be t-2j ?? 10:01

    • @edilmarlulab7079
      @edilmarlulab7079 4 года назад

      Use trigo. Identities
      from sin(T)sin(t-T)
      let A=T & B=t-T
      Then Subtract to get sinAsinB:
      cos(A-B) = cosAcosB + sinAsinB
      cos(A+B) = cosAcosB - sinAsinB
      cos(A-B) - cos(A+B) = 2sin(A)sin(B)
      sin(A)sin(B) = 1/2[cos(A-B) - cos(A+B)]
      Then Substitute: (A = T ; B = t-T)
      sin(T)sin(t-T) = 1/2{cos[(T) - (t - T)] - cos[(T) + (t - T)]}
      Then you get:
      sin(T)sin(t-T) = 1/2[cos(2T - t) - cos(t)]

  • @armanfahradyan6207
    @armanfahradyan6207 Год назад

    Great video, but actually I think sin function on your T-shirt is flipped, it is -sin ))

  • @brandonklevans7473
    @brandonklevans7473 2 года назад

    Awesome shirt