Finally a teacher who could explain this concept CLEARLY. Very very very thanks Mr. Van Veen. Teaching something to someone and comprehending what it is are completely different SKILLS. Not everyone should be allowed to be teacher! Thanks again sir!
Is there a rule on what the time index values should be? For example, if I want to take the DFT of x(n) = cos(n) with a window of n = 0, 1, 2? Can I just sample once per second?
I don’t know what’s going on and what you meant, but when you plug in a function to the inverse function you get the original value, alas x[n] and by no means you shall omit the formula of the sum of DFT from calculation of the inverse function. x[n] shall be a signal, but it turns to be the frequency domain for your calculation in DFT and it falls apart to be the signal - same x[n] for your calculation in DTFT. I hope I don’t distract the learning process for anyone, but someone who wrote about Fourier Series on Wikipedia in my native language has already succeeded to confuse 1000 EE students, so just watch ahead. I was wondering why such a good video has 28 dislikes, though I found out the source of the downvotes. Thanks though for working hard in explaining, the first 2.5 minutes indeed helped.
The continuous-time version of this result is shown in Lecture 9 of the Introduction and Background playlist, "Properties of Fourier Transforms", starting at about 9:15. The specific case of an impulse train is an example used to illustrate finding the FT for periodic signals. The DT case is very similar. I can't recall at the moment if I show the DT version anywhere. Let me know if this doesn't answer your question.
I wish someday that Artificial Intelligence Engineering Physics mathematical Software will make a real world computerized simulation/animation with the aid of high tech 'SPECTRUM ANALYZERS / Vector Network Analyzers, of this type of too much complex topic to understand.
The DFT is sometimes called a discrete-time Fourier series, but in the signal processing field it is more common to use the name DFT. I agree it is not the "best" terminology, but it is established now and would be pretty difficult to try to change it.
Dear Barry I need to calculate heart rate variability by using fast Fourier transformation and find total power and High frequency and Low frequency. ex) x=[0.465,0.466,0.470,0.500] How can I do that for above example.
Hmm, I'm not sure I understand your question. Specific questions like this are often appropriate for the "signal processing stack exchange" forum. UA-cam won't let me post the url, but if you google what I put in quotes you should find it easily. But you will have to give more details about your problem so people can understand it. Good luck.
Finally a teacher who could explain this concept CLEARLY. Very very very thanks Mr. Van Veen. Teaching something to someone and comprehending what it is are completely different SKILLS. Not everyone should be allowed to be teacher! Thanks again sir!
Very well explained! Reading that same topic from a book for hours couldnt solve my problems. Now i got it! Thank you!
this is one of the best videos on UA-cam.thanks man
That's exactly what I was looking for!! Thank you so much =D
This is exactly what I wanted ! Thank you :)
Thank you!!! This is awesome, I just found you and you have saved my semester. Eres mi puuto Mario Castroo de PDS!
You gave me confidence in this topic. Thanks!
great service to students sir...continue the good work
Super clear. Keep the good work
Thank you so much for your excellent explanation!
Pretty amusing when you google something about a class, only to find a youtube video from your professor.
He is your professor? Lucky!
You cats are on the right groove with compression, there could be some amazing discoveries there.
goddd, tnx man ,this helped in so many ways!!! ❤❤❤
Great explanation, thank you very much
Very precisely explained!
Thank you so much professor
I love how he goes all in on the owners and chefs but always stays respectful towards the wait
what
perfect video thank you so much!
very well explained
thank you so much. such a great job :))
Great teacher, no dounbt
Thank you very much!!!!
Amazing!
I was wondering why your name looked so familiar. then i realized i own a copy of the first editions of your book. too cool.
I can try if you tell me a time in the video and an equation. I'm not sure what you are referring to exactly.
Bless your soul
Thank you.
Correct me if I'm wrong, but I believe JPEG usues DCT, not DFT
now i understand dft!!!
Is there a rule on what the time index values should be? For example, if I want to take the DFT of x(n) = cos(n) with a window of n = 0, 1, 2? Can I just sample once per second?
Thanks for the great video, Barry!
I don’t know what’s going on and what you meant, but when you plug in a function to the inverse function you get the original value, alas x[n] and by no means you shall omit the formula of the sum of DFT from calculation of the inverse function. x[n] shall be a signal, but it turns to be the frequency domain for your calculation in DFT and it falls apart to be the signal - same x[n] for your calculation in DTFT. I hope I don’t distract the learning process for anyone, but someone who wrote about Fourier Series on Wikipedia in my native language has already succeeded to confuse 1000 EE students, so just watch ahead. I was wondering why such a good video has 28 dislikes, though I found out the source of the downvotes. Thanks though for working hard in explaining, the first 2.5 minutes indeed helped.
Thank you sir
thank you
thank You.
Ole Samir Kaddoura talked about this at Montverde, and Eddie Leibler, Hector Montalban chimed in too.
can anyone explain what is define in this procedure? does this mean we can define anything??
Superb explanation. Thanks!
perfect.
how if DTFT from the signal that priodic?
How do u plot mag and phase of DTFT?
ُThanks .. I love it .
What is meant by finite duration?
Why is it okay to sample the frequency as 2*pi*k/N? Because then since k
My exponential maths skills are minimal at best... I'd appreciate if you kinda explain how the other parts of the summation went to zero...
Why it starts from n=0 and not negative values? Can anyone explain?
4:35-5:40
In my calculation of DFT
X[2]=-1, not 0.
Is the picture of DFM 7:36 right?
But the right question how to choose M in DTFT we choose the it using Shannon's theorem
at 7:51, the DTFT and DFT chart, should the unit of x-axis be rads, instead of rads/s?
It should be rads for DTFT. DFT x-axis does not have any units
Thanks Easwar Sankar!
Hello Barry, can you direct me to where you show that DTFT'{impulse train} = impulse train?
The continuous-time version of this result is shown in Lecture 9 of the Introduction and Background playlist, "Properties of Fourier Transforms", starting at about 9:15. The specific case of an impulse train is an example used to illustrate finding the FT for periodic signals. The DT case is very similar. I can't recall at the moment if I show the DT version anywhere. Let me know if this doesn't answer your question.
for DTFT, i dont understand how you get X(jw)=4 when k=0, since shouldnt sin(0)/sin(0) =0 ? can you explain? thanks
0/0 is an indeterminate form, so you have to use L'Hopital's rule or look at the limit as k->0 to get the value
or you can use sinc function as an alternate.
Don't fight the feeling
Hello.. can I have the matlab code for the DTFT and DFT representation of this video.. thanks..
Please contact me directly through email with these sorts of requests.
for DFT, shouldnt X[k]=2 when k=2?
no, e^{-j pi} = e^{-j3pi} = -1, and e^{-j2pi} = 1, so it sums to zero when k=2
I wish someday that Artificial Intelligence Engineering Physics mathematical Software will make a real world computerized simulation/animation with the aid of high tech 'SPECTRUM ANALYZERS / Vector Network Analyzers, of this type of too much complex topic to understand.
at 15:14 "Click for more great mind-raping content" lol... seriously, thank you
Isn't this a fourier series in descrete time rather than a DTFT?
The DFT is sometimes called a discrete-time Fourier series, but in the signal processing field it is more common to use the name DFT. I agree it is not the "best" terminology, but it is established now and would be pretty difficult to try to change it.
Ok undestood, thank you for your response!
would you like to help me solve the result for DTFT of |cos (phi/6 n)|
Dear Barry I need to calculate heart rate variability by using fast Fourier transformation and find total power and High frequency and Low frequency.
ex)
x=[0.465,0.466,0.470,0.500]
How can I do that for above example.
Hmm, I'm not sure I understand your question. Specific questions like this are often appropriate for the "signal processing stack exchange" forum. UA-cam won't let me post the url, but if you google what I put in quotes you should find it easily. But you will have to give more details about your problem so people can understand it. Good luck.
and i thought signal processing is soooo annoying.........sir all student from south africa say thank you.(www.dut.ac.za)
po
Thank you so much...!!!!
thank you sir