Community Profile # Torsten

Last seen: Today Active since 2013

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how to incorporate boundary conditions as constraints in fmincon optimization?
I think with the mixture of numerical, symbolic and optimization variables it is easier to set up the problem directly. x0 = [ ...

4 hours ago | 0

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Newtons Method but error message "Singular Matrix"
This is quite a tricky problem - even with the MATLAB solvers available. For given V and theta at t = 0, integrate until x beco...

6 hours ago | 1

Fsolve Recommending Algorithm I Already Specified
You overwrite the previously set options with this line options = optimoptions('fsolve', 'Display', 'none', 'TolFun', 1e-6, 'To...

10 hours ago | 1

How can i use this vector in my ODE function?
Integrate from t=0 to t=10 and use u = 30. Restart the ode solver with the solution at t = 10 and integrate from t=10 to t = 20...

1 day ago | 0

Simulating a 1D Random Walk
% Step 2: Plot the entire trajectory for a single random walk N = 100; % Number of steps single_trajectory = simulateRandomWal...

1 day ago | 0

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How to plot different length vectors against each other?
However the x vector has a length of 113 compared to 1849 for y because of the differences in timestep. Solve for x and y toget...

1 day ago | 0

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Error using linprog (line 369)

1 day ago | 0

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95% confidence bounds from logistic curve (curve fitter) give different results to plotting via equation in script
It's not possible to just insert lower and upper bounds for the parameters into the model equation to get the curves for the con...

1 day ago | 0

how to calculate the drivative of discretized ODE
After the line sol = ode45(@(t,u) dODE(t, u, par, tau, M,D), tspan, u0,options); you can compute the derivatives of the soluti...

1 day ago | 0

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There is an error when i run my 'subplot' command in MATLAB
Rename your script file "subplot.m" to something else. "subplot" is a reserved name in MATLAB.

2 days ago | 1

You don't supply k1, k2, c1 and c2 to the objective function. If these are the parameters to be optimized, you don't need to pa...

2 days ago | 1

1D HEAT CONDUCTION
In each time step, you have to solve the linear system of equations T(1,k+1) = Tleft T(i, k+1) - deltat/deltax^2*alpha* (T(i-...

2 days ago | 1

Finding a definite integral
x = linspace(0,1,101); u = [0.1600 0.1600 0.1599 0.1599 0.1597 0.1596 0.1594 0.1592 ... 0.1590 0.1...

2 days ago | 0

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Compute a function that has Double summation
All the series involved are geometric series for which the finite and infinite sums are known: sum_{i=1}^{i=n} q^i = q * (1-q^n...

3 days ago | 0

What does this mean: K12_global(1:3:6,1:3:6)?
Do you see what happens ? The new matrix K12 is formed of the elements (1,1),(1+3,1),(1,1+3) and (1+3,1+3) of the original mat...

3 days ago | 0

Unable to meet integration tolerances without reducing the step size below the smallest value allowed (1.136868e-13) at time t.
I had to add the line global alpha pD K g_T IFN at the beginning of your program to make the code work because the above globa...

3 days ago | 0

Numerical Differentiation using Finite Differences
h = 0.01; x = 0:h:2*pi; fx = sin(x); %df1 = (sin(x+h) - sin(h))/h; df1 = (sin(x+h) - sin(x))/h; df2 = (sin(x) - sin(x-h...

3 days ago | 0

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Efficiently evaluating ODE event that depends on only some variables
Use OutputFcn to check your condition after each successful time step. But I think it will be difficult to check for complanari...

3 days ago | 0

Finding real and imaginary part of an equation
U = 0:0.1:10; P = sqrt((((20*U.^2)-15) + sqrt((400*U.^4)+ (1080*U.^2) + 25 -600 - 450 - (1125./U.^2)))./((36*U.^2) + 30)); Pim...

4 days ago | 0

I have a code related to thermodynamic subject, i don't know how to run it in order to get the different plot out of it. for example plot (p,rho). plot of pressure vs density.
I think there is something wrong in the calculation of the compressibility factor. p = EOS(2.0,150) function p=EOS(rho,temp)...

4 days ago | 0

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compute sums by accumulating in a for-loop
sum(xprime(1:100-l)) This is a scalar. sum(xprime(1:100-l)).*xprime(1+l:100) This is a vector of length 100-(1+l)+1. (sum(xp...

4 days ago | 0

Financial optimization of heston
Assuming that Price_SV returns a vector of the same size as P_data, your call would look somehow like fun =@(p)Price_SV(p(1), p...

4 days ago | 0

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I don't know why this code is saying, "Arrays have incompatible sizes for this operation."
Your vector of initial conditions is 6x1 y0 = [Pi; Si; Li; Ii; Ri; Bi]; but you only return a 5x1 vector in PSLIR dydt = [dPd...

6 days ago | 0

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Use off_diagonal = coefficient * ones(N-1, 1); instead of off_diagonal = coefficient * ones(N-2, 1); See the example "Create...

6 days ago | 0

Apply fmincon nonlinear parameter inequality constraints into SimBiology for parameterization
function [c,ceq] = nonlincon(params) %Nonlinear inequality constraints c(1) = params(1)*params(2) - params(5)*params(7); % For...

6 days ago | 0

Trouble with For Loop
for i = 1:35 dataN_(i) = ecg_data (:,i); mean_HR_subject(i) = ... ... end

6 days ago | 0

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Solving first order ODE with initial conditions and symbolic function
You solved it in your code. The second solution out of the three MATLAB returned is the "correct" one giving real-valued tempera...

6 days ago | 0

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It takes too long to run the program and in the end I get an error, could you tell me what the error is?
You can't change the input for x in function "campo_pendulo". So you can delete this part of your code because it doesn't influ...

6 days ago | 0

Can someone help me check if I did this correctly?
Replace syms r a0 by syms r a0 positive to get the limits resolved.

6 days ago | 0

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