This was a truly incredible explanation, and I can't tell you how enlightening I found your animations. I'm so glad you decided to share your wisdom on UA-cam, and judging from the other comments, many many people have been grateful!
David . You have a rare talent . You have a talent for communication . You take something that is complex and make it understandable . Great voice as well ,very clear .
This is probably the best lecture series on signals and system ever put on internet. Very useful to get the intuitive knowledge of all the concepts. Please keep making more videos on Laplace, convolution and so on, which will give intuitive perspective of the equations.
I am an Electrical Engineer. Proudly say that this is the most amazing video regarding Z-transform, i ever watched. What a noble way to teach with proper fitting examples . WOW !! I know Z-transform very well, but still i can say I LEARNT A LOT :)
I'm about to graduate with my degree in Electrical Engineering at Oregon State University. I've had to watch hundreds(yes, literally hundreds) of videos to understand that concepts i've had to learn since i'm a slow learner, and i can say with complete confidence that this is the absolute best and most intuitive description of the Z transform i've seen.
It's been a while i was looking for an explanation with visual interpretation, there is some videos about Z-transform, but yours is the most comprehensive one ;) thanks
Watch the 12 min video in 2 hours, but learn things that confused me for 5 years! Hope I can thumb up for 1000 times. Thank you for your excellent work, David!
I just came across this video in 2022, and the fact that you mentioned a year that was before the pandemic kind of struck me in an odd way. In any case, I hope that you have been doing well.
It is great that you came here. Believe me, this video series is one of the best explanation on z Transform available in the Internet. Please watch all the five videos. It is really worth it.
Well done to anyone who can endure these videos (it's a bit of a marathon exercise!) Hopefully they provide some insight and help develop a deeper understanding of the z-transform
This is brilliant. I wish there was just a second of pause between topics and changing the visual, but nonetheless you make it extraordinarily clear (and youtube has a pause button, anyway).
Magnificent David.... ! really help me to visualize what z transform is. please release it's second part asap.. Also I want to know the practical example of discrete system that you have shown in video
Maybe I am missing something: there is a theorem about transfer functions which says if all the singularities of the function lays inside the circle with |z|
5:22-5:26 Did example of the signal z^-n (for z=0.9e^jx=-0.9+0j) plot correctly? z = (-0.9)^-n for n={0, 1, 2, 3, 4, ...} z = {(-0.9)^0, (-0.9)^-1, (-0.9)^-2, (-0.9)^-3, (-0.9)^-4, ...} z = (1; -1.11; 1.23; -1.37; 1,52; ...}
Nice vid! Nonetheless, I have one question: in the video you state that z=r*e^(jw), but (please correct me if I'm wrong) the euler identity is that e^(j*ANGLE)=fasor, so one should say that z=r*e^(j*(w*t)), where t is time. z is a fasor of radius r and angular velocity w, and that's why you can have a sinusoidal signal if you plot that on time.
I know it's been a few years but I just came across your comment and was curious. Since z is just a complex number and not a time-varying function, I don't think you'd want to put a t (or n) in it's definition. Therefore it would just be z = r*e^(jw) and not z = r*e^(jwt) or z = r*e^(jwn). We can still apply Euler's formula, since the argument of the exponential is complex, and get that z = r*e^(jw) = r*(cos(w) + j*sin(w)). However, if we're thinking about *powers* of z, where z is raised to -n, then we'd get that z^(-n) = (r*e^(jw))^(-n) = r^(-n) * (e^(jw))^(-n) = r^(-n) * e^(-jwn) = r^(-n) * (cos(-wn) + j*sin(-wn)). And since cosine is an even function and sine is odd, that would be equivalent to r^(-n) * (cos(wn) - j*sin(wn)).
Fantastic video. I've been looking for an intuitive interpretation for a while. Thanks. I'm not sure how he pronounces the 'r' variable (something like "or"). It looks like a regular 'r'... What is it?.
Great video about the insight what Z-Tx is actually doing, however, I do have this question; at 11:24, the animation of the sinusoid shows an oscillating signal with some frequency when z is almost equal to -1+0j. Shouldn't the signal at this point have zero frequency because of the imaginary part equal to zero?
Great explanation!!, do you have some explanation of the discrete wavelet transform using the lifting scheme? , becoming more important every year, and a lot of us would be really helped by your explanation, cheers
Good video but I am confuzzled... at 4 minutes you say [1,1,1...] is a DC signal, which you use for the two sets of correlations. Then at just before 5 minutes you say the outcome of the correlation is 0, which indicates there is no DC component present in the signal, which I sort of took to mean, no DC input components, but that makes no sense... or does it? or did you mean the output signal?
Almost 10/10 in terms of content, crisply delivered, great ideas, you were clear on how r^-n controls the exponential growth or decay, I wish you had talked about why we have BOTH a cos and a sin in (cos(wn)-sin(wn)), together they contribute to the oscillation, one would be enough if we just wanted oscillating decay. like the second term is just phase shifted version. Maybe something to do with how together those two form an orthogonal basis? The phase shifting seems to encode the information regarding which direction of the imaginary axis that frequency is selected. It's not clear at all to me and I hope anyone who decides to use david's great video as a template decides to go a bit deeper in that. I think it might have been better to think of the complex part as a complex phasor spinning at a rate of w Hz rather than as the seperate cos or sin terms. If I did not know 3b1b I would not know what levels of animation is possible, so I have higher expectations from you. Still Thanks so much.
You basically need the cosine and sine to capture sinusoidal oscillations of any phase shift. We can represent a sinusoidally oscillating waveform mathematically as Acos(wt + p), where p is the phase shift. Such a waveform is also equal to (Acos(p))cos(wt) - (Asin(p))sin(wt). Hope this helps.
Professor David Dorran, I´m looking for chirp z-transform (CZT). How does it work? Where and when I need to use? Could you explain a little bit about this or indicate some book (or site) to study? Thank you very much. Best regards.
I haven't used the CZT before. I did some reading on it when you made the post and from that would suggest that you first make sure you understand the DFT (which effectively analyses signals against a set of sinusoidal basis functions) and then try to appreciate the view of the DFT as being a sampled version of the Z-plane around the unit circle (This video might help with that - but its not explicitly clear I have to say). From my brief reading the CZT is similar to the DFT except that can be determined by sampling the Z-plane along a path that corresponds to points that ensure that the ratio of the damping factor to frequency are maintained as a constant. This corresponds to points that lie on a straight line in the s-plane if you were to map these points from the z-plane on to the s-plane. The DFT can be viewed as a special case of the CZT since the unit circle in the z-plane maps on to the imaginary axis in the s-plane i.e. a straight line but the damping factor is zero in the case of the DFT.
Professor, thanks for the fast answer. I think that the link for the video did not come. I would appreciate if you could put it again. I really need to understand how does it work. I need to use the vectors produced by CZT , DFT and maybe Walsh transform comparing the results in process that I am developing to calculate active power. Best regards.
See ua-cam.com/video/2RZWvy5p3ts/v-deo.html for an explanation of the statement on why "the impulse function contains all sinusoidal frequency components"
David Dorran Thanks 😀 I have seen it and I understood why we use impulse signal . When my professor was teaching about impulse response he never told us why we use 'impulse signal'. You're videos are awesome because you answer the 'whys' and don't simply jump to conclusions. 👍
There's just magic equations that just appear, and after that equation is said, with spurious reasons given for the pursuit of some result that seems random, a next magic equation appears. sure it is probably all logical but it just does not connect to anything practical that i can see.
I came across some Z transform videos on my way here. They were pretty useless to me as I was searching for Zed, but maybe you'll find them of interest: ua-cam.com/video/y6120QOlsfU/v-deo.html
This was a truly incredible explanation, and I can't tell you how enlightening I found your animations. I'm so glad you decided to share your wisdom on UA-cam, and judging from the other comments, many many people have been grateful!
David . You have a rare talent . You have a talent for communication . You take something that is complex and make it understandable . Great voice as well ,very clear .
Thanks Eamon. Nice to get that feedback.
This is unbelievably useful, detailed, yet top down. You are sent from the heavens thank you!
No other materials explain Z transform better than this one. This really help me a lot! Thanks David!
Thanks York. I'm glad it helped!
@@ddorran after 5 years he's still replying. legend.
absolute legend
@@upsidedowns2342
This is probably the best lecture series on signals and system ever put on internet. Very useful to get the intuitive knowledge of all the concepts. Please keep making more videos on Laplace, convolution and so on, which will give intuitive perspective of the equations.
I am an Electrical Engineer. Proudly say that this is the most amazing video regarding Z-transform, i ever watched. What a noble way to teach with proper fitting examples . WOW !! I know Z-transform very well, but still i can say I LEARNT A LOT :)
I'm about to graduate with my degree in Electrical Engineering at Oregon State University. I've had to watch hundreds(yes, literally hundreds) of videos to understand that concepts i've had to learn since i'm a slow learner, and i can say with complete confidence that this is the absolute best and most intuitive description of the Z transform i've seen.
Thanks Dakotah! Good luck with your career as an Electrical engineer!
I understand more now than I did in 3 months of control lectures, thank you for putting all the pieces together
Taught me what my professor couldn't in a whole semester. Wish i had you as my professor ;] great vids!
By far the best, impeccable explanation of z-transformation and its usage. Thank you for video. Keep up the good work! :)
It is the best explanation about Z-transform! thank you David
It's been a while i was looking for an explanation with visual interpretation, there is some videos about Z-transform, but yours is the most comprehensive one ;) thanks
Watch the 12 min video in 2 hours, but learn things that confused me for 5 years!
Hope I can thumb up for 1000 times.
Thank you for your excellent work, David!
Thanks for that!
Incredible. What a clear and comprehensive video. I learned quite a lot and really think it'll help advance my understanding of z-transforms.
Great to get that feedback Chris. Thanks!
truly great material! no better video to explain the z transform than this one !
No words to thank you. Exceptionally good.
Wow thank you very much. The first one and a half minute about systems stable/unstable were worth it.
Great job! Very clear explanations that give a lot of intuition..in 12 mins you made me understand what my professors couldn't in a whole semester!
Thanks for the great explanation. Made it a lot easier for me to understand what Z-transform is useful for.
Thank you so much. Brilliant explanation.
I wish every professor could explain these concepts so well.
Thank you so much for this video and for the series. I finally get the Z Transform. This is the best explanation yet.
Great to hear that it's helping people out Jason.
I love it. wonderful review of the z-transform. great animations.
Thanks Richard!
Marvelous video, David! I hadn't learnt about the Z-Transform before, but your explanation really helped get me started. Thank you, and happy 2017!
I just came across this video in 2022, and the fact that you mentioned a year that was before the pandemic kind of struck me in an odd way. In any case, I hope that you have been doing well.
Crystal clear explanation. You're a hero.
Thanks Tim!
It is great that you came here. Believe me, this video series is one of the best explanation on z Transform available in the Internet. Please watch all the five videos. It is really worth it.
Well done to anyone who can endure these videos (it's a bit of a marathon exercise!) Hopefully they provide some insight and help develop a deeper understanding of the z-transform
Absolute perfection description of Z-transform
beyond z-transform that i knew before. great explanation
It was really too much effective, thank you so much for sharing your great knowledge points with us.
Really helpful.
What a true gem on the Internet!
Great explanation, very clear and helpful. Thank you.
this is just simply amazing, looking forward to the part II. cheers
Excellent video! God bless you sir! I think I finally understand this!!
WOW. The wikipedia article on this should have a link to this.
Thank you for your perfect English. God bless you!
This is brilliant. I wish there was just a second of pause between topics and changing the visual, but nonetheless you make it extraordinarily clear (and youtube has a pause button, anyway).
Magnificent David.... ! really help me to visualize what z transform is. please release it's second part asap..
Also I want to know the practical example of discrete system that you have shown in video
Damn this is really making everything click in my head. Thanks David.
Thank you for this video. In this week I’m not planning to watch all of your videos ;) especially regarding Z transform and Matlab. Great job!
Maybe I am missing something: there is a theorem about transfer functions which says if all the singularities of the function lays inside the circle with |z|
he was discussing the values of Z, while stability depends on values of Z^1 .... when |Z| |Z^1| >1 and vice versa
This video might help answer this ua-cam.com/video/dEJp46SFgV4/v-deo.html
SUPPPPPPPPPPPPER ! DSP TEACHERS ALL OVER THE WORLD MUST SEE THIS VIDEO
5:22-5:26
Did example of the signal z^-n (for z=0.9e^jx=-0.9+0j) plot correctly?
z = (-0.9)^-n for n={0, 1, 2, 3, 4, ...}
z = {(-0.9)^0, (-0.9)^-1, (-0.9)^-2, (-0.9)^-3, (-0.9)^-4, ...}
z = (1; -1.11; 1.23; -1.37; 1,52;
...}
Nice vid! Nonetheless, I have one question: in the video you state that z=r*e^(jw), but (please correct me if I'm wrong) the euler identity is that e^(j*ANGLE)=fasor, so one should say that z=r*e^(j*(w*t)), where t is time. z is a fasor of radius r and angular velocity w, and that's why you can have a sinusoidal signal if you plot that on time.
I know it's been a few years but I just came across your comment and was curious. Since z is just a complex number and not a time-varying function, I don't think you'd want to put a t (or n) in it's definition. Therefore it would just be z = r*e^(jw) and not z = r*e^(jwt) or z = r*e^(jwn). We can still apply Euler's formula, since the argument of the exponential is complex, and get that z = r*e^(jw) = r*(cos(w) + j*sin(w)). However, if we're thinking about *powers* of z, where z is raised to -n, then we'd get that z^(-n) = (r*e^(jw))^(-n) = r^(-n) * (e^(jw))^(-n) = r^(-n) * e^(-jwn) = r^(-n) * (cos(-wn) + j*sin(-wn)). And since cosine is an even function and sine is odd, that would be equivalent to r^(-n) * (cos(wn) - j*sin(wn)).
Fantastic video. I've been looking for an intuitive interpretation for a while. Thanks. I'm not sure how he pronounces the 'r' variable (something like "or"). It looks like a regular 'r'... What is it?.
Great video about the insight what Z-Tx is actually doing, however, I do have this question; at 11:24, the animation of the sinusoid shows an oscillating signal with some frequency when z is almost equal to -1+0j. Shouldn't the signal at this point have zero frequency because of the imaginary part equal to zero?
Tremendous video .. nice work 🎉
Awesome video. Gives a good perspective on Z-transform. When are you planning for part 2?
ua-cam.com/video/WCxM4SYsg1w/v-deo.html
10:23, if Z is a constant real number such as 0.8, shouldn't the 2nd graph be a straight line at 0.8? Why does it curve up towards the end?
If z is a constant 0.8 then the signal z^-n is the sequence {0.8^0 0.8^-1 0.8^-2 0.8^-3 ...} = { 1 1.2500 1.5625 1.9531 2.4414 ....}
Great explanation!!, do you have some explanation of the discrete wavelet transform using the lifting scheme? , becoming more important every year, and a lot of us would be really helped by your explanation, cheers
this explanation is so good
very helpful session , looking forward part 2 . thanks
Hey where are the other part of this videos. Plz post them asap. Plz N make video on laplace transform and Fourier transform also
ua-cam.com/video/WCxM4SYsg1w/v-deo.html
LIke this, very insightful. Looking forward to the part 2.
Making this shit argument understandable is an act of heroism. Thanks man, you are a Hero!!!
where is the part 2 ?????
Great Great piece of work on Z- Transform . Like this Video more than my whole D.S.P lectures...+++++
Good video but I am confuzzled... at 4 minutes you say [1,1,1...] is a DC signal, which you use for the two sets of correlations. Then at just before 5 minutes you say the outcome of the correlation is 0, which indicates there is no DC component present in the signal, which I sort of took to mean, no DC input components, but that makes no sense... or does it? or did you mean the output signal?
your lecture is realy amazing.sir what can we say about the significance of z transform in power system protecyion
explained very well...👍
Ty bro, God bless you.
Almost 10/10 in terms of content, crisply delivered, great ideas, you were clear on how r^-n controls the exponential growth or decay, I wish you had talked about why we have BOTH a cos and a sin in (cos(wn)-sin(wn)), together they contribute to the oscillation, one would be enough if we just wanted oscillating decay. like the second term is just phase shifted version. Maybe something to do with how together those two form an orthogonal basis? The phase shifting seems to encode the information regarding which direction of the imaginary axis that frequency is selected. It's not clear at all to me and I hope anyone who decides to use david's great video as a template decides to go a bit deeper in that.
I think it might have been better to think of the complex part as a complex phasor spinning at a rate of w Hz rather than as the seperate cos or sin terms.
If I did not know 3b1b I would not know what levels of animation is possible, so I have higher expectations from you. Still Thanks so much.
You basically need the cosine and sine to capture sinusoidal oscillations of any phase shift. We can represent a sinusoidally oscillating waveform mathematically as Acos(wt + p), where p is the phase shift. Such a waveform is also equal to (Acos(p))cos(wt) - (Asin(p))sin(wt). Hope this helps.
@@ddorran oh thanks man, yea it helps :)
Professor David Dorran,
I´m looking for chirp z-transform (CZT). How does it work? Where and when I need to use? Could you explain a little bit about this or indicate some book (or site) to study? Thank you very much. Best regards.
I haven't used the CZT before. I did some reading on it when you made the post and from that would suggest that you first make sure you understand the DFT (which effectively analyses signals against a set of sinusoidal basis functions) and then try to appreciate the view of the DFT as being a sampled version of the Z-plane around the unit circle (This video might help with that - but its not explicitly clear I have to say).
From my brief reading the CZT is similar to the DFT except that can be determined by sampling the Z-plane along a path that corresponds to points that ensure that the ratio of the damping factor to frequency are maintained as a constant. This corresponds to points that lie on a straight line in the s-plane if you were to map these points from the z-plane on to the s-plane.
The DFT can be viewed as a special case of the CZT since the unit circle in the z-plane maps on to the imaginary axis in the s-plane i.e. a straight line but the damping factor is zero in the case of the DFT.
Professor, thanks for the fast answer. I think that the link for the video did not come. I would appreciate if you could put it again. I really need to understand how does it work. I need to use the vectors produced by CZT , DFT and maybe Walsh transform comparing the results in process that I am developing to calculate active power. Best regards.
unipd? qualcuno?
amazing material. Waiting for part 2
Thanks so much for the amazing work. :)
How is e^(j*pi/2) = j?
e^{j*pi/2} = cos(pi/2)+j(sin(pi/2) (using eulers formula)
cos(pi/2) = 0
sin(pi/2) = 1
=> e^{j*pi/2} = j
Very nice video. Thanks a lot
Amazing!
Thankx David
You are awesome ! thanks
Great, Thanks
This is so good
Where's part 2?
ua-cam.com/video/WCxM4SYsg1w/v-deo.html
I wanna see part 2 as well... it helps me alot thanks
+AngeloYeo It'll be a while before I get a chance to do part 2 I'm afraid.
and finally you are back! :)
ua-cam.com/video/WCxM4SYsg1w/v-deo.html
great explanation
what a great video! thank you!
Thanks alot 💖
Great job!
great explanation
thank you
JUST AMAIZING
That was really good.. Appreciate the effort.. :)
Awesome David.Keep Going
really good video..thanks!!
Hey man thank you for this video.
are you irish?
Sound a lot like people in peaky blinders
Part 2 please
ua-cam.com/video/WCxM4SYsg1w/v-deo.html
great work ! keep it up!
See ua-cam.com/video/2RZWvy5p3ts/v-deo.html for an explanation of the statement on why "the impulse function contains all sinusoidal frequency components"
David Dorran Thanks 😀 I have seen it and I understood why we use impulse signal . When my professor was teaching about impulse response he never told us why we use 'impulse signal'. You're videos are awesome because you answer the 'whys' and don't simply jump to conclusions. 👍
thanks
very nice explanation, thank you xD
Fantastic !!
your accent is wild, but your explanation on the topic was very helpful review for my understanding for my FE review
great tutoring..,,,,,just one point to mention...could you please speak slowly...english is my 5th language,,,cheers
Thank you sir :-)
There's just magic equations that just appear, and after that equation is said, with spurious reasons given for the pursuit of some result that seems random, a next magic equation appears. sure it is probably all logical but it just does not connect to anything practical that i can see.
I always get teachers who are concerned in solving rather than y to solve
T H A N K Y O U.
Stewie
Brain Overheating!!
This title is misleading. I'm just looking for a video explaining the Z Transform ffs. I don't care about this whole "Zed Transform" thing.
Is this a joke or do you not know that in some places 'Z' is pronounced as 'zed?'
it's a bad joke clearly
I came across some Z transform videos on my way here. They were pretty useless to me as I was searching for Zed, but maybe you'll find them of interest:
ua-cam.com/video/y6120QOlsfU/v-deo.html
Nice non-Indian accent, just sayin