Community Profile # Paul

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Inconsistency between the FFT results and the analytic spectrum of a Gaussian function
Hi Sherwin, fft assumes the input sequence starts at k = 0, so we have to apply ifftshift on the input to fft. fs = 10; t = -...

3 days ago | 1

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How to plug x^2+y^2 in to euler's Method
Hi Michael, Focusing only on the error message ... this line is the source of the error f(i) = x.^(2).*(i)+y.^(2).*(i); ...

4 days ago | 0

Solving symbolic third order polynomial
Hi Axel, What is the source for the equations in red? Here is Matlab's solution: syms q(t) a0 a1 a2 a3 q0 q1 dq0 dq1 t0 t1; ...

7 days ago | 0

How to identify transfer function of a motor with IODelay?
Hi Erik, Here's what I tried: Load the data load forum.mat Run the script so I can operate on the same variables. Take note ...

7 days ago | 1

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Solving symbolically for variables that are equal to several equations
Hmm. Don't know why solve doesn't find a solution, syms xi v r a mu spec_eng1 = [xi == (v^2)/2-mu/r, xi == -mu/(2*a)] solve(s...

10 days ago | 0

I am trying to get my function to return two variables to the workspace. It is a very simple function. What am I doing wrong.
If you want both outputs returned, use ouput arguments on the call [m,n] = save_13(1,2) When you call a function without outpu...

10 days ago | 0

Simulink - output of a block as an another block parameter
Hi Wiktor, Some Simulink blocks have parameters that can be specified either internally or externally, such as the Integrator b...

11 days ago | 0

Hello, I want to use the LPC function to achieve AR pre-whitening, will the AR coefficient obtained by fftfilt filtering signal is a residual signal?
Hello Yx Y, Based only on reading the lpc example, it would seem that the call to fftfilt should be xest = fftfilt([0 -a(2:end...

12 days ago | 0

Using Fourier Series write a MATLAB function to synthesize the wave-form in problem (2-19), Assume A = 4mV. Your function should take n ( # of harmonics ) and produce a plot
Hi Evan First, check your code that defines one period of v(t). It''s probably easier to define v(t) using piecewise syms t T...

12 days ago | 0

Use of syms, piecewise & conv commands
Hi Ben, First you have to decide if you want to solve the problem for a closed form expression using symbolic tools, like syms ...

12 days ago | 0

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how to get the correct plot of function sin(N+1)*pi*x^2/sin(pi*x)^2 with different N
Hi Daniel, I think you are correct that the limit of y as x approaches any integer is (N+1)^2. However, all the compuations are...

13 days ago | 0

Repeat array onto the same row
A=[1,2,3,4] horzcat(A,A) horzcat(A,A(1:floor(numel(A)/2))) % or use ceils depending on how you want to handle the case where ...

14 days ago | 1

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How to plot FFT?
Hi Sara, The frequency vector needs to be corrected. And for this data it's helpful to subtract out the mean before taking the...

14 days ago | 0

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Fourier analysis of an spwm signal
Hi Mosharof, Load the data load spwm_one_cycle.mat Plot the differences between time samples. We see that the data is not equ...

16 days ago | 0

transform the cell 'string' containing strings into a single string
load string.mat who string string_new = join(horzcat(string{:})) Probably not a good idea to have a variable named string, w...

17 days ago | 1

Hi Niusha Here is the first part of the code: Fs = 1e3; t = 0:0.001:1-0.001; x = cos(2*pi*100*t)+sin(2*pi*202.5*t); xdft = ...

17 days ago | 1

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calculate wrong or "/" work different
Hi pipor The ldivide, .\ and mldivide, \, which is what you're actually using here, for the scalar case are mathematically (tho...

20 days ago | 0

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How to get the eigenvalues of a transfer funciton matrix
Hi 宇航 杨, Considering that question 1 is about the "eigenvalues of a transfer function matrix", I would say that defining what t...

22 days ago | 0

Why does frequency spectrum gets flipped in STFT compared to the one generated from FFT?
Using random data rng(100); Matrix = rand(1000,1); Compute the stft [s,f,t] = stft(Matrix,5000/3,Window=rectwin(32),OverlapL...

23 days ago | 0

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Stability margins for a cascaded system with getLoopTransfer functions
Hi Daam, To get the stability margins at 'e', I believe this is correct: Le = getLoopTransfer(CL,'e',-1); % open-loop function...

24 days ago | 1

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Fourier transform of an impulse response function
Hi Jason, syms t tau f real % SYSTEM I'd use heaviside, but piecewise works too. h = piecewise(t>=0, 0.01005*(exp(-t))*si...

24 days ago | 0

I have 4 input channels (time series) and two output channels (time series) form test. I would like to calculate transfer function using tfestimate (MIMO).
Hi Dhiren, Have you tried the 'mimo' option of tfestimate (link to doc page) ?

25 days ago | 0

Does Error Message Depend on Whether or Not Function is Executed Inside Try/Catch?
I put in a service request to Tech Support on this question. Their answer was that the error that's returned to the user does, o...

1 month ago | 1

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Saving signals for each case of parsim() simulation
Hi TeraWatt, 1) Not sure what the issue is. I created a simple model with one logged signal. Ran the following script (R2022a)...

1 month ago | 0

Problems with the creation of a randomic signal
Hi Andrea, How are you defining the bandwdith? fs=200000; %sampling frequency B = 5000; %bandwidth rng(1); n = 1e4; % no...

1 month ago | 0

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Hello, I have problem with odeToVectorField in ODE second order system of equations.
The problem is confusion between sym expressions and symfun objects. g= 9.81; m= 0.468; Ix= 4.856e-3; Iy= 4.856e-3; Iz= 8....

1 month ago | 0

Try using exist: function y = fcn(u) coder.extrinsic('exist'); fileexists = 100.0; % dummy assignment to specify fileexist...

1 month ago | 0

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Question

Does Error Message Depend on Whether or Not Function is Executed Inside Try/Catch?
This call to diff resolves to symbolic diff syms s diff(@(s) 1/(s+1),s) which diff(@(s) 1/(s+1),s) I guess the parser sees t...

1 month ago | 1 answer | 0