Stephan

Last seen: Today

1,336 total contributions since 2017

Knowledge means knowing where it is written...

Interested in:
- Optimization
- Mathematical Modelling
- Improvement of my programming skills

Stephan's Badges

Answered
Inserting Elements in middle of 1-D, 2-D, N-D Array
This may help https://de.mathworks.com/help/matlab/ref/griddedinterpolant.html X = [ 1.0 2.0 3.0 4.0 5.0 6.0 7....

13 minutes ago | 0

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delete elements from the given array
X(2:2:end-1) = []

1 hour ago | 0

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Solver stopped prematurely. fmincon stopped because it exceeded the function evaluation limit, options.MaxFunctionEvaluations = 3.000000e+03.
You have to give the options to the solver and to insert the MaxFunctionEvaluations Option into the optimoptions struct: MyValu...

1 hour ago | 0

Answered
Hi everyone! How do i want to plot graph the graph for this values?
To plot single points use scatter: x = 5 y = 2 scatter(x,y) plot can not visualize single points, but vectors: x = 5:10 y ...

1 hour ago | 0

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Error using dde23 : Derivative and history vectors have different lengths.
You did not define your constants - i took some fake values for them. n and T are unused. Also for good reasons, try to avoid gl...

20 hours ago | 0

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Is it possible to vectorize this loop?
w_new = (sum(w + A.*B(:),2))';

23 hours ago | 0

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How can I solve this BVP problem which is second-order ODE with variable coefficient?
Your function handle appears to be incorrect: syms y(x) eq = diff(y,x,2) + ((1-10*x^2)/x)*diff(y,x,1) == 0; [V,S] = odeToVect...

24 hours ago | 0

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Error using odearguments (line 93) must return a column vector
Add this line in your ode function at the last line: NameOfYourOutputVariable = NameOfYourOutputVariable(:); This should...

3 days ago | 0

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Error using odearguments (line 93) BANANA must return a column vector.
You make a vector of R1 with size 1x391 in the BANANA function. Thus you have a vector of 1x391 as result - one entry for every ...

4 days ago | 0

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Answered
How to solve Error - Index in position 1 is invalid. Array indices must be positive integers or logical values.
A1 = load('Mtxj_FULL_ASCENDING.txt'); A2 = load('Mtxj_FULL_DESCENDING.txt'); B1 = load('N2j1c_FULL_ASCENDING.txt'); B2 = load...

4 days ago | 1

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Answered
Solving a matrix equation with a parameter in the coefficient matrix
syms theta S F r = 0.025; h = 0.3; rho = 7850; g = 9.81; m = r^2 * pi * h * rho; phi = atan((0.15 - 0.15*sin(theta))/(0....

4 days ago | 0

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Answered
How to solve this error while using ode15s.
%prob settings lb=[0 0 0 0 0 0 ]; ub= [100 120 1 100 110 20 ]; % parameters for differential evolution np=10; it=100; cr...

4 days ago | 0

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Answered
Curve fitting with custom equation, not using toolbox
This example shows how to curve fit with the inbuilt basic function <https://de.mathworks.com/help/matlab/ref/fminsearch.html |*...

4 days ago | 0

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Minimize a function with 2 variables and 2 inequality constraints.
<https://de.mathworks.com/help/optim/ug/fmincon.html *|fmincon|*> appears to be the right choice for this. Note that you in fact...

4 days ago | 0

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Answered
My code says too many output arguments
Give your functions outputs: newton function newton x0 = input('Enter the initial guess value, x: '); tolerance = input('E...

5 days ago | 0

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How to fit the data points into a closed curve?
This will not solve your problem finally, but it shows a possible way to tackle this. The idea here is to use a cardiod curve an...

5 days ago | 0

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Removing specific rows from a matrix where its corresponding element in another column is zero.
ans = abc; ans(abc(:,3)==0,:) = []

5 days ago | 0

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Answered
plot surface using different x,y vector increment and got different graph
You did not multiply elementwise, also you can shorten your code a little bit: fun = @(x,y) -1.448-0.477*x-0.4757*y+0.1473*x.^2...

5 days ago | 1

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Is the graph correct for the distance 10km for the okumura model?
There is a publication at FEX which you could use to check your code: https://de.mathworks.com/matlabcentral/fileexchange/28423...

5 days ago | 0

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how to plot a function symbolically?
g = 9.8; r = -10:0.1:10; H = -10:0.1:10; C = -10:0.1:10; fun = @(r,H,C) H - C.^2./(2*g*r.^2); z_r = fun(r,1,1); z_H = ...

5 days ago | 0

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why when i plot the graph for the okumura model it doesnt show line?
f is a scalar here - for this reason you have only one data point. Either use scatter to visualize the point or make f an array ...

5 days ago | 0

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Answered
Unable to convert the text to datetime using the format: 'dd-MM-yyyy hh:mm'
datetime('22-9-2020 10:35','InputFormat','dd-MM-yy HH:mm') datetime('22-9-2020 15:48','InputFormat','dd-MM-yy HH:mm') ans = ...

6 days ago | 0

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Answered
How do I plot given points using a functions?
x = [1,12,2,6,5] y = [5,23,5,6,3] plot(x,y) % Using a function handle y_fun = @(x) 3.*x + 5; y_vals = y_fun(x); plot(x, ...

6 days ago | 0

Answered
Solve the equation for x
Make the changes suggested in the answer from KSSV and use vpasolve: syms x p = 0.89; a = 6.7; v = 26.12; r = 0.07; L = 78...

6 days ago | 1

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How can I solve this two shaded equations for d1 and d2?
syms d1 d2 Grin eq = [d2 == Grin * d1; (d1+d2) / 2 == 0.15]; sol = solve(eq,[d1,d2]); sol_d1 = sol.d1 sol_d2 = sol.d2

6 days ago | 0

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Alzheimer detection from brain mri image
Have a look at FEX: https://de.mathworks.com/matlabcentral/fileexchange/55107-brain-mri-tumor-detection-and-classification htt...

6 days ago | 0

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how to plot three figures in single figure?
r=[12 23 45 67 77] p=[44 55 66 77 88 ] g=[21 33 23 34 54] k=[55 45 43 23 12] figure plot(r) hold on plot(p) plot(g) plo...

6 days ago | 1

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Answered
Errors using ode45
%Define PMOIs Ix = 2887; %kg-m^2 Iy = 2887; %kg-m^2 Iz = 5106; %km-m^2 %Define initial conditions x1_0 = 0.6; % OmegaX ...

6 days ago | 0

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Answered
GA does not solve problems with integer and equality constraints.
Reformulate your constraints: <https://de.mathworks.com/help/gads/mixed-integer-optimization.html#bs1clc2>

7 days ago | 0

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Answered
Error using sym/subsindex () while using the symsum function
There are two possible ways in Matlab, that allow a syntax like V(k) The first is indexing with a variable like in a for loop:...

7 days ago | 0