Hello to all registering for the daily study group. Looking forward to working with you soon. Let me know if you have questions about the course.

TO EVERYONE (STUDENTS) Above I place some links. I do recommend checking the MIT free Course on Signal and system Why? it aligns with this study group in the Topics, you can download each Chapter and Video and the professor is Professor Oppenheim. I am sure you can find the entire Book not chapter by Chapter.

To download faster use "Chrome" or IE 11 (not Microsoft edge) so that you use "right click and save the MP4 videos". Any Other course free in the MIT you can download videos and resources. They have over 600 courses free (good for refresh material if you have attended any engineering school).

If you use Microsoft edge, you will not see the download link and will default to ply the Video. Also check this link https://fourierandwavelets.org/ and download the free two Books and the Matematica books with the PDF. They will complement the learning on this study group. The Workbook ZIP/TAR provide is just the syntax under Mathematica along with the exercise. I will attend the Fridays class and sporadic during he week.

https://ocw.mit.edu/courses/res-6-007-signals-and-systems-spring-2011/pages/introduction/ Instructor: Prof. Alan V. Oppenheim
Course Number: RES.6-007 Departments: Supplemental Resources
As Taught In: Spring 2011

Hi Jacek, in general the notebooks may have more examples compared to the presentation. Here is the missing example for L09:

Hello Hakan, please take a look at the attached notebook and let me know if you have more questions.

Hello Mariusz Do you have suggestions for reference materials such as books, online, etc? Thank you, John

I agreed with you. The Original link from MIT is the query for all Recorded Classes (free) to Download materials and Video as a complement lecture.
(MAIN) https://ocw.mit.edu/search/?q=signal+and+systems From the Author of the great book Prof Oppenheim's recordings (1 ) https://ocw.mit.edu/courses/res-6-007-signals-and-systems-spring-2011/ (2 ) https://ocw.mit.edu/courses/6-341-discrete-time-signal-processing-fall-2005/ (3 ) https://ocw.mit.edu/courses/res-6-008-digital-signal-processing-spring-2011/ Others Professor Dennis (4 ) https://ocw.mit.edu/courses/6-003-signals-and-systems-fall-2011/ Professor Derek (5 ) https://ocw.mit.edu/courses/2-161-signal-processing-continuous-and-discrete-fall-2008/

Now, Every Single Courses in Digital Filters, etc., always introduce to the basic Concepts found in a single book by Professor Oppenheim. Even as a review, we must place the time, but with the MIT VIDEOS recorded and download it, the 1-hour Study Review using the Mathematica Notebooks, I believe they complement. I took several years ago all these courses in Signal and System, and at the graduated level in other DSP courses, we go back to the basic Foundations of "Signal and Systems". What I like from MIT are the lecture notes, exercise and Solutions, in addition to the video recordings. Been the basic foundations, it doesn't matter if they were recorded 10 years ago.

I'm a little confused about the solution to Exercise 6 (the last) in L07CTSolutionMethods.

Find the solution of the following nonhomogeneous differential equation with given initial conditions:

y''(t)+Sqrt[2]y'(t)+y(t)=sin(t), 	y'(0)=0, y(0)=0

The forcing function is sin(t) but in the solution the DSolveValue has the equation with "Sin[t] * UnitStep[t]" (i.e. UnitStep[t] is added):

DSolveValue[{y''[t] + Sqrt[2] y'[t] + y[t] == Sin[t] UnitStep[t], 
   y'[0] == 0, y[0] == 0}, y[t], t] // Simplify

Why is the UnitStep function added to the equation here? Are there some underlying assumptions about this question that I've missed?

Hakan, thanks for catching that. The problem statement should in fact include the unit step as part of the forcing function (as it does in Problem 5). While it is not strictly necessary when solving with Mathematica, I like to explicitly include the unit step to clearly indicate that the onset of the input is at t=0.

If of any help, I checked for eventually different output emerging from different input and, as it is seen below, we get the same result:

Zbigniew Kabala: Yeah ... Solutions to Initial Value Problems with jump/step functions as input (non-homogeneous term) are defined in terms of Heaviside Functions in WL & Mathematica. These solutions are not defined at the jump points ... what means that the solution is not continuous at these points. This is NOT CONSISTENT with the requirement that solutions to DEs must be continuous. How do we reconcile the use of Heaviside Function with the fact that SOLUTIONS (functions satisfying the Differential Equation) MUST be differentiable at every point? This kind of trouble would not occur if the solutions were given in terms of the Step Functions instead. I remember questioning something like this in a previous "Daily Study Group" on Differential Equations ... "Week Review" ... the speaker at that time did not seem to get the point or I was not able to make the point clear. It may be a convenience for further dealing with the "Convergence Theorems" when applying "Fourier Series" or "Fourier Transforms". Of course this choice does not seems to me that change any of these mathematical inconsistencies. Thanks for bringing this point back to discussion! Best regards!

Thanks Zbigniew for bringing this up.

In case you missed today's online session, we've released six of the eight course quizzes, for the material covered during the first three weeks of this Study Group. Successful completion of all eight quizzes is required to earn a certificate. Check your recording notification email today for links to the quizzes.

Looking forward to any discussion, but please send any technical questions about the auto-graded quizzes by email to wolfram-u@wolfram.com, so we can address those directly. Also, we ask that everyone refrain from discussing specific quiz questions on this Community forum. Thanks!

HI, Looking forward to this study group, but i will not be in every session Live! Impossible. I do all my important thing early in the morning which conflict with the time in some day. For me, it will be a great Review, in addition to learn Matematica since what i have used in the past is MATLAB.

References: There are too many books in Signal and System and many of them using Matlab. So Ignore Matlab and learn to transfer to Mathematica. The study group has already has all the book prepare. Thank you!!!!!!!!!! This is great.

BOOK: 1. Check Proakis,
2. Another is M.J Robert "Signal and System" but ignore MATLAB and learn Mathematica (what I will be doing, personally). 3. SCHAUMS's series has a great paperback "Signal and systems" . I always buy a paperback low cost for every course i have taken in my life, from electronics, physic, chemistry, control etc.

Below several links of webpages dedicated to signals and systems http://www.dspguide.com/pdfbook.htm (DSP GUIDE --goes thru Signal and systems) https://www.thefouriertransform.com https://lpsa.swarthmore.edu (La Place) https://fourierandwavelets.org/ https://ocw.mit.edu/search/?q=signal+and+systems (MIT free recorded courses)

Will there be exercises available to download? Thank you, John

Hi John, That is correct. For each lesson (except for L01) you will have a set of exercises, shared after the session is completed.

Thank you, Leila Enjoyed your class today. I am new this topic and new to Mathematica. This class will be helpful for both.

Hello:

I am traveling and only have the cloud available to me for Mathematica. Furthermore, I do not have the availability, with my subscription to the cloud, to upload notebooks into my cloud account. Consequently, I will not be able to reviewing the exercises and their solutions in "notebook" format and that is why I asked if the exercises and their solutions could be made available in possibly PDF format.

Thanks,

Mitch Sandlin

Thanks, John! Glad to hear that.

Hi be aware: If we play the recorded Video, The Polls doesn't show at all. So, when the discussion continues, we do not have an idea what were the choices or what were the results.one thing that is my goal is to be able to get something in the Wolfram syntax (the Fun part). I see it is powerful, but I never have use it.

I see the Notebooks Clear in the Video, but when opening the files, there are a bunch of Brackets in the right side that i would like to eliminate. This is like MATLAB scrips.

Thanks

Hi Jacek, the exercises start with Lesson 2, we did not create an exercise notebook for the introductory lesson.

Dziękuje!

Where do you place that? there are no 'SetOption' menus. I look in the "Preference" submenu to see if there is a checkbox for formatting etc. For me,it is too annoying those brackets. I am used to MATHCAD and clean sheets. MATHCAD has been discontinuing by PTC in favor of their Junky Mathcad Prime, I dislike that S/W big time, sorry). They are years away to make it like Mathcad.

So, I am migrating from a Math Program to type equations as they are seen. Something that I cannot do it in MATLAB. MATHEMATICA is like Mathcad with Floating Pallets plus the powerful syntax, just as any software package, we must learn to use the "short notation' and menus.

Hi, do we need to turn in the "exercises" notebooks or is it only for our own practicing and learning?

Arturo, They are for just for practice, nothing to turn in. Later in the course, they will post quizzes to be completed online and these will count towards the certificate of course completion. Steve

Hi;

What was the answer to Poll #1 of Lesson 6. As an aside, it would be helpful if the speaker in speaking, would slow down a little and place a little more emphasis on articulation.

Any update on getting the exercises in a PDF format?

Thanks,

Mitch Sandlin

To what extent the course's focus is going to continue on electrical circuits (this is seemingly such an old content XIX/XX c. :-) ) ? Such focus seems unnecessary (and it may be create a barrier for some people) in order to get at signal types/characteristics and signal processing. Though I am an electrical engineer by original training, my current interest in signal processing is more general. My specific interest is from the perspective of analyzing human neuro-physiological signals and the systems I study are human-machine systems. Hence my domain agnostic interest in signal processing.

Also: Are we going to get to multiresolution wavelet analysis?

Thanks - Jacek

Hi;

As a work-around until the PDF's of the Example Notebooks are available, could my Wolfram Cloud Account be expanded so that I could open the course notebooks and review them, at least for the duration of the course?

Thanks,

Mitchell Sandlin

[WSG22] Daily Study Group: Signals, Systems and Signal Processing

Hi Leila, I have the files with exercises and lessons. yes, the most up to date ones. But some of them do not contain important parts which you demonstrate. For example today's lessons file L09CTConvolution.nb did not have the first example in which you used Sin functions. In the cases of other lessons the difference was more minor. Thanks - Jacek

Sometimes there seems to be little correlation between the video and the lesson notebooks eg Convolution.

Is there a notebook of the video lecture that corresponds to L09CTConvolution.nb ?

Hi Jacek, yes, the continuous-time part of signals and systems has not changed much or any in the past 30-40 years. In the nineties, discrete-time concepts were added in recognition of the importance of DSP. It has remained in this form since then without I think losing any of its relevance. It still is a necessary gateway to topics in communication, digital signal processing, image processing, control, etc.

Thanks! how do I download it to a local .nb file? When I click on download and select "Continue with FIle Download" it downloads something, but it is not an .nb file - for me it looks like ".com.google.Chrome.tU6ZVD"

You are replying on a totally different topic. I am talking about a link to a "Embedded Notebook" from a reply in this forum. Download does not work for me.

Click on "Make your own copy" to open a copy of the notebook in Cloud. Then File> Download. You could also click on a cell bracket here in the notebook, copy the cell and paste it into your own notebook.

I copied the following as input text. Without attaching the notebook, how do I copy and post WL input like this to our community group so it is more readable and also easy for readers to copy and execute in a notebook?

GraphicsGrid[Table[
  DiscretePlot[((2/3)^(n/2) Subscript[\[ConstantC], 1] + (-1)^
       n (2/3)^(n/2) Subscript[\[ConstantC], 2]) UnitStep[n], {n, -5, 
    20}, PlotRange -> {-2, 2}, PlotStyle -> PointSize[0.02`], 
   AxesLabel -> {n, y}, ImageSize -> {400, 400}, 
   PlotLabel -> ("\!\(\*SubscriptBox[\(\[ConstantC]\), \(1\)]\) = " <>
       ToString[N[Subscript[\[ConstantC], 1], 2]] <> 
      ", \!\(\*SubscriptBox[\(\[ConstantC]\), \(2\)]\) = " <> 
      ToString[
       N[Subscript[\[ConstantC], 2], 2]])], {Subscript[\[ConstantC], 
   1], {-1, 1/2, 3/2}}, {Subscript[\[ConstantC], 
   2], {-1, 1/3, -3/2}}]]

Same here.

Regretfully I need to unsubscribe from the Signal Processing study group. I thought I would have time to participate, but my current schedule will not allow.

Hello Rui and welcome! If you have signed up for the study group you will receive emails with the updated material. If you have registered and have not received the material, please send an email to our Wolfram U team at wolfram-u@wolfram.com.

Can we get Fridays recording please (Week 2 Review and Fourier Series)

Could you please release the Vid for June 1st, as it is still not available.

Works fine for me on the Wolfram Cloud

RSolveValue[y[n] - \[Alpha] y[n-1] == 0, y[n], n]
(* \[Alpha]^(-1 + n) C[1] *)

Most likely you have an existing definition for y or \[Alpha]. Try ClearAll["Global`*"] or "Restart Session" from the "Evaluation" menu, or Quit[].

In both of today's lessons - Lessons 26 and 27, about Z-transforms and inverse Z-transforms - the functionTransferFunctionModel (https://reference.wolfram.com/language/ref/TransferFunctionModel.html) was used to get zeros/poles of a function, but there was no comment or explanation of the function.

It seems to be a very useful and versatile function. It is also used in Lessons 32 and 33, so perhaps it will be explained more in connection to these lessons?

Would someone post the link to today's recording of the lesson Z-Transform and Z-Transform Theorems? I wasn't able to attend and don't see the email for the recording. Sincerely, Jay Morreale

The links of all recordings of the study sessions can be found on this page.

The link you're looking for can be found here.

I have two questions:

(1) In the interface for this community share, next to the "Add Notebook" icon is an icon to add a code sample. When I place my cursor over it, it states "Code Sample < pre> < code> Ctrl+K". Please explain exactly how to use this to enter a readable code sample. When I try it, I get the same thing as when I just copy and paste. (I am using the Google Chrome browser.) For example, I get the following:

Subscript[X, \[Delta]](j \[Omega])=1/(2 \[Pi]) \[ScriptCapitalF]{x(t)}*\[ScriptCapitalF]{Subscript[x, \[Delta]](t)}

(2) In file L30_Sampling.nb, I have two questions about the derivation following the cell that states "The Fourier transform of the signal Subscriptx, [Delta] may now be obtained by making use of the Fourier transform time-multiplication theorem (symbol * denotes convolution):" In the first line of the derivation should the argument of the rightmost Fourier transform be Subscript[Delta], T rather than Subscriptx, [Delta] ? Second, please show the detailed steps used to derive the Fourier transform of Subscript[Delta], T as shown in the second line of the derivation. (I assume linearity is used so that the derivation involves transforming the individual terms in the definition of Subscript[Delta], T.)

Excellent! Thanks, Jamie.

Hi @Arturo Pazmino, We will look into this. Thanks

The missing L31 course video is a known issue that we expect to resolve by next week. I want to remind our Daily Study Group participants that logging watched videos in the course is NOT a requirement for your completion certificate. As a Study Group participant, you need only to pass the course quizzes.

Hi, I have a few questions about the quiz: Quiz3 Q10 in my framework, I think x[n] should be delta[n]-delta[n-1]+2delta[n-3], then I got the correct answer, otherwise, even the length of convolve won't match...

Quiz4 Q4, the answer differs from the defination in course video, where there should be a factor of 2Pi times the "correct" answer.

Quiz4 Q5, I'm not sure if the answer is based on a different defination of FT, because I won't get the coefficient of sqrt[2/Pi]

And by the way, I pass all the quizzes, but how can I get the cetification doc? like a PDF version?