Paul

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191 total contributions since 2011

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Answered
Designing LQR controller error
The system might be controllable in principle, but in reality seems to be problematic for using state feedback. I had trouble ev...

11 hours ago | 0

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How can I plot the transfer function? HELP Please.
Because you want to make plots, I'm going to assume that you have numerical values for each parameter in your model. For exampl...

3 days ago | 1

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How should I create a Transfer function with nth order polynomial term in denominator in simulink?
The power operator works for SISO tf and zpk objects. For example: >> h=exp(-0.2*tf('s'))*zpk([],-1,1)^5 h = ...

4 days ago | 0

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why my plot is not correct?
If you're looking for a plot with odd symmetry, try: plot(x,nthroot(x,3)) % check doc nthroot for details

5 days ago | 1

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Display rotation matrix with s1, c1, etc. in place of sind(theta1), cosd(theta1), etc. respectively.
Use subs: >> doc subs >> syms theta1 s1 c1 >> A=[cos(theta1) sin(theta1);-sin(theta1) cos(theta1)] A = [ cos(theta1)...

5 days ago | 0

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Why is the convolution so different from the analytical answer?
When approximating the continuous convolution with a discrete convoluton, the discrete convolution needs to be multilplied by dt...

6 days ago | 1

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Plotting responses other than step responses to transfer function
Looks like an fplot() confusion issue. This code results in the expected plot: >> syms t; y(t) = ilaplace(1/s*poly2sym(T.Numera...

6 days ago | 0

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Find the 5-point DFT of the sequence:
The code posted has a few issues. The second line is: >> u = sin(j) u = 0.0000e+00 + 1.1752e+00i >> whos u Name...

8 days ago | 0

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Cannot compute Riccati solution for LQI controller
I'm not sure it's relevant, but should the fifth row of SYS.c be all zeros? I suspect the issue is with stabilizability of the ...

8 days ago | 0

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How to solve a symbolic complex equation with real and imaginary parts?
I'm not sure what "change the paramters of the solve function" means. If a general apprach is desired, maybe something along the...

10 days ago | 1

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Problem with integrating Sin to Cos
If you just want ode in terms of cos() >> ode = int(sin(n*x),x,0,pi/2) ode = (2*sin((pi*n)/4)^2)/n >> rewrite(ode,'...

13 days ago | 0

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Simbolic simplification of trigonometric functions
How about this: >> simplify(f,500) ans = -(sin(x)*(- sin(x)^2 - c)^(1/2)*(sin(x)^2 - 1)^2)/(2*d^2)

13 days ago | 1

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How to generate correlated samples from a single distribution? Each sample should be correlated with the previous.
I don't think the questionn is well posed. The question and the code make it sound like there is a single distribution and the s...

16 days ago | 0

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how can i use symsum to make function with a variable apart from syms k?
This code works for the specified sequences. It would need to be modified if either x[n] or y[n] take on non-zero values for n <...

17 days ago | 0

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Problems with the controllability matrix.
ctrb() in the Control System Toolbox only accepts numeric inputs. If you have numeric values for the variables, you can substit...

17 days ago | 0

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Making a transformation matrix in matrix format
You're not getting 4, 1 x 4 matrices. It just looks like that because of the formatting to the diplay. >> syms th d alph l A...

17 days ago | 0

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How to shift state space models by equilibrium points using ss and lsim?
The states, inputs, and outputs of Sys are all perturbations from the equilibrium solution. The intiial condition to lsim (x0) w...

19 days ago | 0

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Differntial equations and Initial conditions
The initial conditions are set to represent the initial conditions of the system to be simulated. What other considerations migh...

19 days ago | 0

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Matlab Code for DTFT to get frequency response
n, h, and w are all defined as row vectors and the * operator is trying to do matrix multiplication. But what you really want i...

21 days ago | 0

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Help with simplifying a complex symbolic expression
This code eliminates U_j0: [num,den]=numden(term1); newnum = combine(num,'log','IgnoreAnalyticConstraints',true); newterm1 = ...

21 days ago | 0

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Laplace Transform for ODE - RC Circuit
I think that last subs command is getting confused because q is defined as the solution of the ode. I'm not sure why that's a pr...

23 days ago | 1

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Fourier Transformation of dirac comb
There is one too many points in the signal y. If you plot([y y]) and zoom in you'll see the pulse at sample 1001 immediately ...

25 days ago | 1

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Convert s in j*ω in a transfer function
No need to change anything in sys. It is a tf object and either freqresp() or bode() can evaluate sys at s = j*w doc freqresp ...

25 days ago | 1

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How to find DTFT of given sequence in matlab
Assuming that y(n) = 0 for abs(n) > 5, there are are only three values of n for which y(n) is non-zero. Put those values of n an...

26 days ago | 0

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Printing out pi as a symbol in equations instead of the numerical value
If I understand the problem, it appears the idea is to define a function, an_Id, that can be used for both numerical evaluation ...

27 days ago | 0

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probability - execution of an operation
If T has a normal distribution, then doc normcdf can be used to find the probability P(T < t)

27 days ago | 0

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Calculating and Plotting Weibull Distribution Function(wblpdf) with Cell Arrays
Here's an example that you might be able to adapt to your needs. >> params = {[1 2];[2 3];[3 4]}; % define cell array with par...

1 month ago | 0

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Answered
I want to find where the root locus branches cross the y axis.
One option would be to use the return values of rlocus: [r,K]=rlocus(G1) to get a coarse idea of the value of K that results i...

1 month ago | 1

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Answered
Convert transfer function writing form
Maybe something like this: >> H = tf([15 25 1],[5 0 5],-1) H = 15 z^2 + 25 z + 1 ----------------- 5 z^2 + 5...

1 month ago | 1

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Answered
Is it possible to manually connect the ABCD matrices to obtain the ss representation
Need to modify two lines of code as follows: clc; clear all; k = 1; m = 1; b = 1; A = [0 1; -k/m -b/m]; B = [0 1/m]'; C ...

1 month ago | 0

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