Answered
Obtaining the differential equations from graphical representation of the problem
One can implement the equations of motion in Simulink and then use linearize to get the differential equation, but that requires...

2 months ago | 0

Question

Is Assignment from symmatrix/symfunmatrix Consistent with Assignment from sym/symfun ?
I've just started using symmatrix and symfunmatrix and noticed a behavior that I don't understand and seems to be inconsistent w...

2 months ago | 0 answers | 1

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Question

How Does the 'All' Option Affect the Result of Symbolic simplify?
Start with a simple expression syms alpha beta real f = cos(beta)-cos(beta)*cos(alpha)^2 and try to simplify it: simplify(f)...

2 months ago | 1 answer | 0

1

answer

Answered
RC Circuit Simulation in Simulink Shows Incorrect Charging Time
Hi Xiaolong, Disclosure: I did not actually open your model. If you know the fastest system dynamics are on the order of 1e-6,...

3 months ago | 0

Discussion

It is Time for the Symbolic Math Toolbox to Include dot and cross Functions
Edit 15 Oct 2025: Removed incorrect code. Replaced symmatrix2sym and symfunmatrix2symfun with sym and symfun respectively (latte...

3 months ago | 0

Answered
Gibbs-like behaviour with lowpass on long signals
Hi qfn, I think that lowpass, et. al. will result in transients due the large, effective steps at the endpoints. I think this ...

3 months ago | 0

Answered
What frame of reference is the CG input to the IMU in Aerospace pack?
Hi Mats, According to IMU Location the CG input is to be provided in a coordinate frame that is fixed to the body. However, the...

3 months ago | 0

Answered
Indexing based on part of a string
column1 = [1;2;1;2;1]; column2 = ["2025-02 A";"A 2025-02";"B";"a 2025-02 a";"b 2025-02 b"]; T = table(column1,column2) T(T.col...

3 months ago | 1

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Answered
Run multiple Simulink model in parallel
Check out Run Multiple Simulations and links therefrom.

3 months ago | 2

Discussion

Will Disucssions Front End be Updated to be Consistent with Back End?
Apparently, the back end here is running 2025b, hovering over the Run button and the Executing In popup both show R2024a. ver m...

3 months ago | 0

Answered
ilaplace doesn't handle tanh()
Hi Marcel, I attempted to recreate the example with the information provided, but got a different result. syms s syms T posit...

3 months ago | 1

Answered
Control System Designer: Inconsistent Controller Output Step Response
I can recreate these result and uc/r certainly looks incorrect. After exporting the systems to the base workspace I get: >> tf(...

4 months ago | 0

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Answered
tf2sos input argument
Hi Nicolai, As far as I know, discrete time transfer functions in the Signal Processing Toolbox (SPT), whether b/a or sos form,...

4 months ago | 1

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Answered
iztrans not giving correct result?
syms z n The fact that the default value for heaviside(0) = 1/2 doesn't matter here, but should be kept in mid in general. x...

4 months ago | 0

Question

What Is the Behavior of Symbolic nchoosek With n < 0 ?
According to nchoosek:Algorithms "If k < 0 or n – k < 0, nchoosek(n,k) returns 0." syms n k f(n,k) = nchoosek(n,k) Using the...

4 months ago | 1 answer | 1

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answer

Answered
Analytic solution of quatric polynomial does not add up
Hi thejinn1314, simplify-ing the general solution with IgnoreAnalyticConstraints might be useful, though perhaps could cause so...

4 months ago | 0

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Question

Why Does Answers Run Code in 2025a But the Run Button, the "Executing In" Popup, and the "Ran In" Tag Still Show 2024b?
ver

4 months ago | 1 answer | 3

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Answered
Numerical precision issues when using tf('s')
I thin the general recommendation is that zpk is superior to tf, and that ss is superior to both. See Using the Right Model Repr...

4 months ago | 1

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Question

How Do Assignment and Deletion Work with an Empty Index on the Left Hand Side ?
I've always thought that indexing with an empty array on the LHS of an = is a no-op for the variable on the LHS (there could be ...

4 months ago | 1 answer | 0

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answer

Question

Must a Function be in Scope Before Creating a Handle to It?
The doc page Create Function Handle states: "Keep the following in mind when creating handles to functions: Scope — The functi...

4 months ago | 1 answer | 1

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Answered
Different Output using For Loop vs Elementwise operation
x = linspace(0,pi,100); y = cos(x); This probably isn't what you want. Perhaps you mean z = zeros(size(x)) or something simila...

5 months ago | 0

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Answered
Looking for an efficient way to run Simulink on thousands of independent files
If I'm understanding the workflow correctly, it seems like you could set up a loop to read in each mat file and set the appropri...

5 months ago | 0

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Answered
Making random to work like randi
I wonder why makedist doesn't support Uniform Distribution (Discrete). But random can be called with that distribution. N_clus...

5 months ago | 1

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Answered
Use case for eval that double/subs does not satisfy
Hi Stephen, Check out matlabFunction syms x1(t) x2(t) k12 k21 k20 k01 conds = [x1(0) == k01; x2(0) == 0]; eqn1 = diff(x1) ==...

5 months ago | 3

Answered
Unexpected Perturbation of Constant Inputs During Full-System Linearization
Hi Gabriele, I wasn't able to create a simple model to replicate the problem, so I can't say for sure that what follows is 100%...

5 months ago | 0

Answered
How to avoid redefining optimoptions in Simulink for real-time nonlinear optimization with fmincon (SQP)?
Are you really using a Matlab Function block? If so have you tried: function y = fcn(u) persistent options if isempty(opti...

5 months ago | 1

Answered
How to correct numerical errors when using a chain of integrators in simulink
The initial conditions on the integrators need to be set to appropriate values to yield the expected result. Define the yellow ...

5 months ago | 1

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Answered
How can I get the correct answer for int(1/x) with symbolic integration?
Seems like the OP might be missing a sign(x), though I'm not really sure how to intrepret this result. syms x real d = diff(lo...

5 months ago | 0

Answered
SubSystem block does not have a parameter named 'MATLABFunction'
The function code in the Matlab Function block can be modified programatically using MATLABFunctionConfiguration

5 months ago | 0

Answered
Question about entry-wise product of general plant and weighting function matrix using Hinfstruct for multi-objective design
Continuing the discussion from this comment .... To use hinfstruct using the entrywise multiplicaiton of T(s) and W(s), it seem...

5 months ago | 0