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How to find the correct magnitude/frequency value for FFT when there has noise?
Hi Hantao, Load the data x = readtable('Data.xlsx'); Time = x.Time; Current = x.Current; Plot it figure plot(Time,Current...

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Why is FFT result divided by NFFT instead of the root of NFFT?
Hi Miktat, The energy spectrum and the amplitude spectrum are two different things. Using the conventions of fft, the output yf...

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Why does cconv perform worse than conv?
I ran this code where cconv outperforms conv for large n n = round(linspace(1e3,1e5,50)); n2 = 2.^(5:nextpow2(n(end))); n = s...

mehr als 3 Jahre vor | 1

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lsim() vs step() : are different responses expected?
The code and the system in the .mat file does not recreate the step plot. There is also an undefined variable. load sys.mat % ...

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What is being "averaged" in the matlab bandpower() function?
Hi Joey, I will confess to only having basic knowledge of this subject and suggest a thorough review of a good textbook. I'll t...

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change class syms to double
Something like this ... e = exp(sym(1)) class(e) format long e = double(e) class(e)

mehr als 3 Jahre vor | 0

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ifft returns NaN when plotting the impulse response function
Hi 粤轩杨, It looks like h_FFT also has a few values that are inf, in addition to the NaNs load("AIF_1.mat"); load("inj_1.mat")...

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Extract first and last row of each subarray in a cell array
I think this works even if the first and last row of a cell are identical. load(websave('cellArray.mat','https://www.mathworks....

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Issues with subs function
I'm sure if you go through it step-by-step, or w/o assigning numbers until the end, you'll see that value of b1 is magical and a...

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plotting a surface between two curve
Hi M, Here's some code to get started. % small curve file_address = 'https://www.mathworks.com/matlabcentral/answers/uploaded...

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convolution without conv function
Questions like this are fairly common on this forum. A closed form expression can be obtained using syms heaviside rectangula...

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fplot and laplace transform
Based on the comment thread in the question, I think the best you can do symbolically would be some something like this: A = [-...

mehr als 3 Jahre vor | 1

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Complex equation in MATLAB (control engineering)
Hi Michael, vpasolve found a solution, even if it's not the one you want. syms s syms w T real F_O = (exp(-s*T))/(s*(1+s)); ...

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how to model this algorithm in simulink?
In the integrator block, set the "Initial Condition Source" to external. Then, connect that source to whatever logic you need t...

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Discretize State Space feedback controller using c2d()
Hi John, lqrd returns the gains for a discrete time controller. The Control System Toolbox cannot model hybrid systems, as far ...

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Matlab function block and integration
If computing the instantaneous power as a function of time, why not feed that into an integerator to find the energy as a functi...

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How to create a sine function from simulink blocks?
Why not just use a Sine Wave block? Would be a lot easier, and you can specify the sample time. The plot you're getting is most...

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Linearize and Transfer Function
Does linearize do what you need? It can be used to linearize a model or a specific block in a model. Not sure how well it works...

mehr als 3 Jahre vor | 1

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remove annotations from diskmarginplot
Hi Muhammad, Something like this might work, either inside or after the loop. Some experimentation may be needed. Disk margin ...

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How do I change variables so that I can differentiate with respect to a derivative?
Hi Curran, The doc page functionalDerivative has related example and shows the problem can be solved like this: % Symbols sy...

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Normalizing an FFT Vector
Hi bil, Define psi syms x real L = 100; psi(x) = sqrt(sym(2)/L)*sin(sym(pi)*x/L)*rectangularPulse(0,L,x); %particle in a box...

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Close loop bode plot
If you have a model of the plant and a model of the controller, it's likely that all that's needed is the feedback command to co...

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How does bandpower() round the input frequencies in variable 'freqrange'?
Hi Joey, bandpower is an .m file, at least in 2022a, so you can inspect the code. My reading is that it will compute the power...

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Symbolic acos( cos(theta) ) does not return theta.
simplify does provide an option that returns theta: syms theta real assume( theta >-1 & theta < 1) a = simplify( acos(cos(the...

mehr als 3 Jahre vor | 0

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I have a transfer function as shown, how do i introduce this block in simulink
Use a Tranport Delay block with Time Delay parameter of 0.2 in series with a Transfer Fcn with Numerator 1 and Denominator [0.1 ...

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I cannot match the calculated from formula FFT with the MATLAB answer though they should be the same
Hi Jonathan Let's define the input signal symbolically clear syms a x w real s1(x) = a*sech(a/sqrt(2)*x) Its Continous Time...

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d2c adding additional states to LTI
Hi Bobby, d2c using either the zoh or foh methods has a constraint that the eigenvalues of the A matrix can't be on the negativ...

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Using rlocus I am confused
Hi Madyson, If you want to draw the root locus for a specific range of gains, then only specify a single range at a time G = t...

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How can I get the parameters of a MATLAB Function programmatically on command line
For a specific Matlab Function block, as asked in the question (I have a simple Matlab Function block in my model with one input...

mehr als 3 Jahre vor | 0

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Simulink State Space Error
Hi Dylan, Unclear why the error message refers to "Project1/Step" when the model apparently does not contain a Step block. Any...

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