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# Kostas

##### Last seen: 4 days ago
24 total contributions since 2019

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Question

Obtain single equation from a system of equations stored as an anonymous function
Hi all, I would like to ask if it is possible to use some sort of notation or other trick, such that I can obtain one of the t...

1 month ago | 1 answer | 0

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Question

How to reshape an array in a specific manner
Hi all, I was trying to reshape an array in a specific manner, however I couldn't accomplish that. Here is the example: I hav...

2 months ago | 2 answers | 0

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Question

Access previous iteration in while loop to derive stopping criterion for differential equation correction-prediction method
Hi all, I have been trying to write a prediction-correction method for matrix differential equations, however I have been unsu...

3 months ago | 1 answer | 0

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Question

ODE45 stop when steady state occurs in a periodic function
Hi all, I have a typical set of equations for a forced spring-mass-damper system, which I have managed to solve successfully. ...

4 months ago | 1 answer | 0

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Question

Too many input arguments for Max function in 2018b
Hi all, I am using the function 'max' in its newest format for 2018b, as shown here, and I have the following code: A = randi...

4 months ago | 1 answer | 0

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Question

Find zeros of numeric function
Hi all, I have a numeric function which for the sake of simplicity resembles the following: x = linspace(1:100) ; y = sin(x...

4 months ago | 1 answer | 0

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Question

ODE45 calculating the total energy in the system and checking the solver
Hi all, I have a simple code written for a 3 degree of freedom damped cart-mass system. My aim is that besides by solving for ...

4 months ago | 1 answer | 0

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Question

Convergence with fsolve?
Hi all, I was trying to solve a system of equations using fsolve that I havent' been succesfull in doing so. So I have the fol...

6 months ago | 0 answers | 0

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Question

Simscape custom component to have one parameters unit change depending on the input of another parameter
Hi all, I am creating a custom simscape block and it all works fine, except the units. The equation is Torq = D1*w + D2*w^PE a...

6 months ago | 0 answers | 0

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How to dynamically size arrays in Simscape custom component?
Have you tried writing right next to your inputs something like: inputs (Size = Variable). I do not know if it works but it is s...

6 months ago | 0

Question

Hi all, I have created a 2 degree of freedom model of an engine driving a propeller with a 'flexible crankshaft' modelled in s...

6 months ago | 0 answers | 0

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How to make a new Simscape model in ".ssc" File.
Well.. I was running into the exact same problem as @Yji Ito and @Chris Matthews run into. After experimenting I managed to get ...

6 months ago | 0

| accepted

Question

Simulink 'To File' Block: How to save simulation outputs as distinct vectors
Hi all, How is it possible to save in simulink a bunch of simulation outpus in the same .mat file (using the 'To File' block),...

6 months ago | 1 answer | 0

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Hi there, Would the code below help? Essentially you can use sprintf function to create a cell array with all the file names...

6 months ago | 0

| accepted

Question

Simulink error: The data abscissae must be distinct and strictly monotonic.
Hi all, I have constructed a simulink model, where within the model I have a MATLAB function block as you can see. Within that ...

6 months ago | 1 answer | 0

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Solver for nonlinear second order ODE has large residuals when mass matrix becomes state dependent
I ended up solving the above equation with sufficiently low residuals, by choosing a sufficiently small tspan and running the od...

6 months ago | 1

| accepted

Question

Solver for nonlinear second order ODE has large residuals when mass matrix becomes state dependent
Hi all, I currently have a nonlinear second order ODE that when I try to solve with any of MATLAB's ODE solvers, I get unaccep...

6 months ago | 2 answers | 0

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Question

ode45 unexpected behaviour for initial conditions = 0
Hi all, I have a code where I am using it to solve the following differential equation: In specific, the above is a 4x4 sys...

6 months ago | 1 answer | 0

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Question

How to determine convergence of ode45
Hi all, I was wondering how it is possible to determine convergence of ode45 for a simple damped mass-spring system. So here i...

7 months ago | 0 answers | 0

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Question

How to extract the value of dydt from ode45 function
Hi all, I have written a code of a damped mass-spring system, that takes as inputs the relevant mass, damping, stiffness and ex...

7 months ago | 1 answer | 0

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Question

Change from set notation to dot notation
Hi all, Just in order to keep uniformity in my code, I would like to know if its possible to change the below expression fro...

8 months ago | 1 answer | 0

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ODE45 Multiple Degrees of Freedom
I have found the problem, and as I suspected, it was in the function. the correct function is: (i still don't fully understand...

8 months ago | 0

Question

ODE45 Multiple Degrees of Freedom
Hi all, I am having difficulty in modelling a 3DOF system usng ODE45 as I am not getting the correct result. Therefore I woul...

8 months ago | 2 answers | 0