# Questions tagged [signal-processing]

Digital signal processing of sound, video or other single or multidimensional data

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1 vote
63 views

### Find the point with the largest slope change

I have a list of x-y data: ...
65 views

### Find knee by intersecting line method

I have an x-y data list. The data is here. It looks like below: I want to mark the knee location. I mean I need to find the point of greatest slope change and get the x coordinate of this point. ...
43 views

### Implement the constant-Q transform in a custom audio encoder

I'm working on a project in Wolfram Language where I need to implement the Constant Q Transform (CQT) in a custom audio encoder. The CQT is a time-frequency analysis method that is often used in music ...
67 views

### Implementing Izhikevich's spiking neuron model

I am trying to implement Izhikevich's simple spiking neuron model which is given by V'(t) = 0.04 V^2+5V+140-u+I u'(t) = a(bv-u) if V=30 mV then V=c, u=u+d ...
1 vote
115 views

### Periodogram and frequency

On the x axis of periodogram, one should have either a period or frequency. What frequency is used in Periodogram --- angular or ...
54 views

### Periodogram returning only 1/0 error

I have a large dataset and would like to get a Periodogram (I saved the data as CloudObject): ...
33 views

### How to find the difference equation from system response or primitive equation?

If I have a system response or the primitive equation , how can i find its difference equation by mathematica? eg: ...
100 views

### Calculation of CIC/FIR filter is too slow

I'm investigating the propeties of Cascoded Integrator Comb (CIC) filter. (for sigma-delta modulator application). I have 2 quesitons and below is what I have done: a). Any alternative method to ...
318 views

### Signal processing from Discrete data (Discrete Fourier Transform)

I am new one to Mathematica. So excuse me if my question is not absolutely accurate. I am trying to find all isolated frequencies in Fourier domain. And then to make inverse Fourier. And finally to ...
377 views

### Problem with Spectrogram

Some time ago I wrote a program to analyse a short segment of music and plot as a spectrogram in Mathematica. It allows one to find the notes in a weird chord for example. The example below is from ...
1 vote
56 views

### Phase unwrapping of transfer function model for calculating group delay [duplicate]

Suppose that I have a transfer function model ...
62 views

### What do we get from OutputResponse[sys {u1,u2}]?

I understand what OutputResponse is doing in the first two examples below. ...
104 views

### What is this this application of KalmanEstimator doing?

I struggle to understand the Kalman filter and the documentation for KalmanEstimator. Please help me understand the first Application on that documentation page. The code in question is copied here: <...
208 views

### Why does this PhaseRange not work?

Any idea why this PhaseRange does not work? BodePlot[-(1/(s + 1000)), PlotLayout -> "Phase", PhaseRange -> {0, 2 \[Pi]}]
59 views

### How to predict the delay of a higher order digital filter

My last question on this was a minimal example. I start with the following: freq=0.1; input=Table[Sin[freq t],{t,1,250}]; I use results above in two digital ...
131 views

### How to predict the delay of a digital filter?

I define a simple digital filter. transferFunction = TransferFunctionModel[{{{0.13793103448275862*z}}, {{-0.9 + z}}}, z,SamplingPeriod -> 1] Then I put samples ...
1 vote
188 views

### How to excite a transfer function with continuous white noise

I'm trying to get the output response of linear system represented by transfer function, once the white noise is given as an input. Here's the code:- For generating continuous noise, I'm getting help ...
77 views

### Why can't I use my discrete lowpass filter?

I am trying demonstrate a discrete IIR lowpass filter using the feature of RecurrenceFilter described here. This is my filter. ...
160 views

### How to conciliate results between Fourier and FourierTransform?

I can't match the analytical results of a continuous-time Fourier transformation with the results I get from a discrete Fourier transform using Fourier[] in ...
132 views

### Play two sounds at the same time in mathematica. For example the inventions of Bach NO.8

I use mathematica to play the Inventions No8 by Bach. I want to play the two parts (by right and left hands )at the same time. But I don't know how to do it. Can you help me? Thank you! ...
101 views

### Finding recurrence relation from an inexact numerical sequence

Consider the recurrence relationship d = 0; d[i_] := (1 + Sqrt[1 + 4 d[i - 1]^2])/2 /; i >= 1 which generates the following sequence (generated by using <...
754 views

### Removing outliers from data

I am trying to remove outliers from the following data: ...
274 views

### Audio Digital Signal Processing

Resource and strategy request I want to identify resources and strategies to implement a Mathematica based solution for audio digital signal processing (DSP) and digital to analog conversion (DAC). ...
1 vote
137 views

### IIR Digital Filter: samples not matching the frequency response

So I am a small project in Mathematica involving a Chebyshev 4th order highpass filter, and to obtain its digital IIR filter with the bilinear transformation. Then I implement the differences equation ...
1 vote
135 views

### Microfluctuations analysis and Power spectrum

I measured a parameter over time and obtained the values below: 0,627896 0,205004 0,259237 1,059125 0,832184 0,587992 0,565537 0,527323 0,460228 0,471958 0,26696 0,75367 ...
1 vote
75 views

### Why do I get this error message from LowpassFilter?

I have a list of numbers data of length 10^7. I have values rate = 100000.; cutoff = 2000.; I try to low pass filter with ...
1 vote
266 views

### Find FT and r.m.s noise of a signal

I have a signal : ...
142 views

### Where to get the "SignalSystem" mathematica package?

I am reading this book: Filter Design for Signal Processing Using MATLAB and Mathematica.It can find on the following link: https://www.wolfram.com/books/profile.cgi?id=3841 It's mathmatica examples ...
116 views

### Building complex signals in Mathematica

How to build a particular signal in Mathematica such that we have a sine curve for half cycle, then have zeros for some time and this continues? It is simple to have the zeros for the second half ...
1 vote
100 views

### How to compute Total Harmonic Distortion (THD) for the following signal?

The signal is as follows Sin[x - j] with $j$ being ...
291 views

### Sampling and filtering data

I'm trying to teach myself about sampling and filtering — and I'm not sure if I'm misunderstanding the concepts or misapplying Wolfram Language. I started by creating a simple test signal with ...
116 views

### How to code a Sum Block when working with Transfer Functions?

I am working using transfer functions models with Mathematica and i am missing a basic feature like the ability to use a Sum Block. How could the model above be modeled? Considering: ...
348 views

### Why doesn't HighpassFilter fully remove the DC component? [duplicate]

The high pass filter is not completely removing the DC component. See the picture. Blue is the signal before filtering, green is after. Here is some background on the subject matter. I'm studying ...
147 views

### How to train each layer in a Neural Network so they optimize different loss functions in an adversarial network?

Example NetGraph to illustrate the idea (Input is an online signal with a value between -1 and 1, Noise is Gaussian Centered at 0 and standard deviation 0.1, EvilNet is constrained to output a value ...
95 views

### Sound steganography with InverseSpectrogram

Here is my code of how to hide a message inside a sound: ...
75 views

### How can I deconvolve a spectrum to get the information about each of the deconvolved spectra?

I have a spectrum with two peaks. I want to deconvolve it by gaussian so that I get the parametres (e.g. peak position, area, FWHM, Height) of each deconvolved spectrum. I have tried the following: <...
1k views

### Can we use Mathematica to design an electronic active filter?

How can we use Mathematica to design an electronic implementation of an active filter?
1 vote
114 views

### How to convolve two audio signal?

Can we obtain reverb effect by convolve two audio signal? Here are some example. https://www.bilibili.com/video/BV1vE411h7W2
172 views

### Are there some programs about inverse Fourier and Laplace transfroms?

To be more exact, I have a function F[w_,s_], where $w$ is the Fourier transform of $x$ and $s$ is the Laplace transform of $t$. Now I want to perform the double inverse transforms $s\to t$ and \$w\to ...
1 vote
65 views

### SpectrogramArray timescale

I have a 600 second @ 8000 Hz WAV file which need to be analyzed in detail in terms of events (red parts in plot) defined in time and frequency that need to be rather exact, in particular the ...
1 vote
68 views

### Is there some programs about the fast inverse descrete time Fourier transform

At first, I give the definition of the inverse discrete-time Fourier transform $$\phi(s)=\frac{1}{2\pi}\int_{-\pi}^{\pi}\exp(iks)f(k)dk$$ Here what I use is ...
1 vote
403 views

### DSP filter problem in the simulation of a Lock-In amplifier

I wanted To explain to students how a Lock-In amplifier works. The best way is to simulate the behaviour of one. However, in my program, I get unexpected behaviour, which I suspect has to do with ...
1 vote
147 views

### Noise filtering in audio

I was given audio with white Gaussian noise and i have to implement two types of filter: Rectangle and Triangle that filter out redundant frequencies and reduce the amount of noise Here is the code ...
196 views

### obtain the phase between two signals [duplicate]

I would like to calculate the phase between two signals like f= Table[Sin[x-0.8],{x,-100,100,0.1}] g= Table[Sin[x],{x,-100,100,0.1}] For doing that I use the <...
299 views

### Amplitude and Phase of a Periodic Signal (Fourier Series) [closed]

Please consider the following periodic signal (by "w" I mean Omega naught): f(t)= Cos(wt)+3sin(2wt)+5cos(6wt) How to plot its amplitude and phase spectrum exactly like the format and pattern ...
1k views

### how to plot the amplitude and phase spectrum of a Fourier Transform in this specific pattern?

I'd like to plot the Amplitude, and phase angle spectrum of the FourierTransform[Exp[-a t] UnitStep[t], t, ω, FourierParameters -> {1, -1}] (The Fourier ...
143 views

### Finding group delay of transfer function

I'm having trouble finding the group delay of a transfer function. I've seen a solved question on here about finding the group delay, but I want to understand why my method doesn't work. Here is some ...
90 views

### How can i use Butterworth filter written in matlab to Mathematica

i need help to convert this code written in matlab about Butterworth filter: ...