# Torsten

Last seen: Today Active since 2013

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Unconstrained minimisation problem with a complicated range
I'll formulate the problem for one property - a generalization to three properties is obvious. I'll assume that each of the 3*N...

8 hours ago | 0

I'm trying to solve a 2nd order ode with ode45, but have no idea where to start.
After dividing your equation by t, you can just follow the example Solve Nonstiff Equation under https://uk.mathworks.com/hel...

9 hours ago | 0

How to solve for 1D non homogenous ODE by Finite element method
I usually set A(1,1) = 1, F(1) = 0, A(N+1,N+1) = 1, F(N+1) = 2 and only loop from 2 to N here: %%%% Assembling %%%% for i=1:...

17 hours ago | 0

How do I change my scalars to fit my normpdf?
xq = 0:100; mu = [25, 50].'; sigma = [5, 10].'; ndist = 1./(sigma*sqrt(2*pi)).*exp(-((xq-mu)./sigma).^2); plot(xq,ndist) g...

1 day ago | 1

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newton raphson for nonlinear heat equation scheme
Why don't you use "pdepe" ? Ten lines of code maximum, and you are done. To get rid of the error in the above code, replace % ...

1 day ago | 0

How to quantify shape similarity between two vectors.
Shift the curves by their means first so that the means of all objects lie in the origin (0). This will remove translational dif...

1 day ago | 0

input appears to be a function and variable and exceeds the number of array elements???
You define a string of length 59 named "input". Then you want to use "input" as the MATLAB command to request user input for "ag...

1 day ago | 0

How to solve for the maximum or minimum value of a symbolic function
syms Vr theta_r Vse rho gamma positive real syms X_r positive real syms n_t positive real syms Vs positive real syms x y l...

2 days ago | 0

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An error 'matlabexecutionerror' occurred when i use 'min' in type optim.problemdef.OptimizationExpression
"min" is not a supported operation for optimization variables: https://uk.mathworks.com/help/optim/ug/supported-operations-on-o...

4 days ago | 0

How do I make x the subject of this function?
D = 0.05; Y = 0.2170535; f = @(X) Y - (D^2 * acos(1-(2*X/D)) - sqrt(X.*(D-X) .* (D-2*X)) / (pi*D^2)); X = 0:0.001:0.025; plo...

4 days ago | 0

Is there a function to create the P-P plot in Matlab, to compare two cumulative distribution functions against each other?
rng default; % for reproducibility a = 0; b = 100; nb = 50; % Create two log-normal distributed random datasets, "x" and "y...

5 days ago | 1

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give correction to my code for finding value of three variable by newton rapson iteration.
The residual for your initial guess is [191,44,534], the residual for the last column of Z is [75e-9,10e-9,9e-12]. Thus obviousl...

6 days ago | 0

Adjacency matrix for ODE45
k = [0,0.1,0.2,0]; reshape(k,2,2) I think you want the reshaped matrix to be reshape(k,2,2).'

6 days ago | 0

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Numerical solution for the heat equation does not match the exact solution
I cannot believe that the value for alpha has no influence on the solution. So I guess that the exact solution maybe holds for...

7 days ago | 2

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When i remove the element wise divison of the RLC beacuse RLC is single array it gives me this error Index exceeds the number of array elements. Index must not exceed 1.
You must keep the elementwise division. So Change Kf_LMax = Kf_Max * (RLC / (1 + RLC)); to Kf_LMax = Kf_Max * (RLC ./ (1 + R...

7 days ago | 0

Computation of left eigenvectors of polyeig
Hint: If you solve for s and x satisfying (A0.'+s*A1.'+...+s^p*Ap.')*x = 0, using polyeig(A0.',A1.',...,Ap.') , it follows...

7 days ago | 0

Setting linear constraints for fmincon,
If real(gamma) and imag(gamma) are vectors of optimization variables, the constraints PS(gamma) - t <= 0; - PS(gamma) - t <...

8 days ago | 0

How to plot temperature along a defined line within a 2D temperature field
Does this help ? https://uk.mathworks.com/matlabcentral/answers/52403-plot-solution-of-pde-toolbox-on-a-line-or-submanifold

9 days ago | 0

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Both function plots start at 1, even though I have time step as t=0:6
Use plot(t,v) plot(t,a) instead of plot(v) plot(a)

9 days ago | 0

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in this code for finding root by newton raphson method i gave derivative of f in g. instead of giving derivative directly how can i get derivative using any code?
syms x f = x^4-x^2-80; g = jacobian(f); f = matlabFunction(f) g = matlabFunction(g)

10 days ago | 0

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how to plot two nonlinear functions
x = -10:0.1:10; y = 0:0.1:20; [X,Y] = meshgrid(x,y); Z1 = X.^2+X.*Y-10; Z2 = Y+3*X.*Y.^2-57; % Visualize the two surfaces ...

10 days ago | 2

Using symbolic solver, I seem to not be able to get a system of equations that give me a desired answer. Does a solution not exist?
It's the same situation as in your other problem: https://uk.mathworks.com/matlabcentral/answers/2138791-how-can-i-find-a-uniqu...

12 days ago | 1

2nd Order Polynomial Coefficient Solving
I don't see R in your regression equation T = a + b*P + c*S + d*S^2 + e*(S*P) + f*(s^2*P) And I assume that "s" means "S". M ...

13 days ago | 2

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limited integration with respect to x in Simulink
As far as I can see, the integral is of the form integral_{x=0}^{x=L} dx / (a*x+b) for some constant values a and b. The anti...

13 days ago | 0

Routh-Hurwitz criterion
Roots of a general polynomial of degree 6 cannot be explicitly computed. You must give numerical values to a,b,c,d,e and f and u...

13 days ago | 0

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paretosearch does not satisfy nonlinear constraints
You may get feasible initial points if you run this code before calling "paretosearch" (maybe for different x0 to get several fe...

15 days ago | 1

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When does an ODE integrator reach the best numerical accuracy?
Solve the problem for different error tolerances and see when the solution stabilizes. If available, also test different solve...

16 days ago | 1

Plot grraph , srink is problem
I don't know what you mean by "I want to change the Y axis value so that the box and plot on x -axis does concide". Maybe like...

17 days ago | 0