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# Paul

Last seen: Today Actif depuis 2011

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Can the Symbolic Math Toolbox Be Used to Prove Matrix Identities?
With the following defintions syms s A = symmatrix('A',3); B = symmatrix('B',[3 1]); C = symmatrix('C',[1 3]); L = symmatri...

1 jour il y a | 1 réponse | 0

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getLoopTransfer is giving the same open loop transfer functions for two different systems
Hi Janki, I'd have to go through the math on the two calls to getLoopTransfer to determine if that result makes sense. Offhand,...

2 jours il y a | 1

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using hasSymType(expression, 'constants') returns true when no constants
Hi Andrew, Both of those examples seem to be in accordance with doc hasSymType and children, except that children returns a cel...

2 jours il y a | 0

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Can't get symbolic numbers.
Hi Austin, Seems to work here as you expect. sym(1/5) sym(1/5,'r') But the preceeding results are based on the default sympr...

2 jours il y a | 1

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FFT is shifting my artificial signal?
Hi Zach, a) create the X vector with spacing based on the sampling frequency, Fs b) create the wave vector with sinusoids comp...

5 jours il y a | 0

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Assigning certain seed value to Simulink Uniform Random Number block in programmatic way
Hi JW, That looks like a typographical error in the doc (which is odd, I've always imagined stuff like that is generated automa...

7 jours il y a | 0

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Number of filter taps in Gaussian filter design
Hi Jay, The doc page for gaussdesign states "The number of symbols between the start and end of the impulse (span) and the num...

8 jours il y a | 0

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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 = -...

12 jours il y a | 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); ...

12 jours il y a | 0

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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; ...

16 jours il y a | 0

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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 ...

16 jours il y a | 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...

18 jours il y a | 0

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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...

18 jours il y a | 0

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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...

19 jours il y a | 0

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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...

20 jours il y a | 0

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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...

20 jours il y a | 0

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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 ...

20 jours il y a | 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...

22 jours il y a | 0

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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 ...

23 jours il y a | 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...

23 jours il y a | 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...

24 jours il y a | 0

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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...

26 jours il y a | 1

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Add zero padding to fft for accurate estimation
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 = ...

26 jours il y a | 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...

29 jours il y a | 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...

environ un mois il y a | 0

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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...

environ un mois il y a | 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...

environ un mois il y a | 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...

environ un mois il y a | 0

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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) ?

environ un mois il y a | 0

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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...

environ un mois il y a | 1

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