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Stephan


441 total contributions since 2017

Knowledge means knowing where it is written...

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

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Answered
How to plot Step response of MIMO system
Hi, if you use: [y_OL,t]=step(sys_OL); you get a matrix as result. To directly plot the step response use: step(sys_OL) Bes...

3 days ago | 1

| accepted

Answered
Confused about atan versus angle- Not getting the same result!
Hi, angle works correctly on complex numbers: atan((.001354/.003453)) atand((.001354/.003453)) angle((.001354i+.003453)) % ...

4 days ago | 0

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Answered
Problem with Gaussian Fit - FWHM extracting
Hi, try this: [Filename,PathName]=uigetfile('*.csv*', 'Multiselect', 'on'); cd(PathName); for k = 1:length(Filename) fi...

4 days ago | 0

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Answered
How to access specific integer values from a String and Convert into Integers?
To get numerical results (integer values) use ymd function: A = "2018-04-24 04:30:00" [Year, Month, Day] = ymd(datetime(A)) g...

4 days ago | 0

Answered
Parameter evaluation in ODE.
Hi, try the attached code. It first evaluates and plots the results of your ode-system with the initial ko values. Then it opti...

6 days ago | 0

Answered
find the number of occurances
y=sum(x(:)==unique(x)) Since 3 is occuring 2 times, the correct result is: y=[3 2 3 1 1] Best regards Stephan

8 days ago | 0

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Answered
How can I make logarithmic fitting without using lsqcurvefit function
Hi, see <https://de.mathworks.com/help/matlab/math/example-curve-fitting-via-optimization.html this example> - it works with ...

12 days ago | 1

Answered
ode45 array size error
Hi, lot of bugs - find the partially fixed version atacched. The ode45 part now runs - but there is a line: du=[eye(p) z...

12 days ago | 0

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Answered
Goodness of Fit Optimisation Problem
Hi, have a read at <https://de.mathworks.com/help/optim/ug/lsqcurvefit.html *|lsqcurvefit|*>. Forget the app - better look at...

12 days ago | 0

Answered
How made the code as easy?
If you want to delete the values at the indicies in P, that are specified in Q use the answer from Madhan above. If you need to ...

12 days ago | 1

Answered
How can I extract two matrices 6x6(unknown) and 6x1(known) multiplied together to form 6x1(known) matrix. As it isn't a square matrix I cannot perform inverse. Kindly suggest what can be done
Hi, there is not a unique solution. Here is an Approach with <https://de.mathworks.com/help/optim/ug/fsolve.html *|fsolve|*>,...

12 days ago | 0

Answered
Using fsolve to solve a set of equations with different constants every time
Hi, make a loop to vary w1 and pass it to fsolve by using one of the options in <https://de.mathworks.com/help/optim/ug/passi...

12 days ago | 1

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Answered
'saveas' does not overwrite existing image file
Hi, see this contribution from *Mathworks Support Team*: <https://de.mathworks.com/matlabcentral/answers/102959-which-func...

13 days ago | 0

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Answered
How to find the roots of large number of polynomials arranged in matrix array
Hi, you could use <https://de.mathworks.com/help/matlab/ref/cellfun.html *|cellfun|*> to apply <https://de.mathworks.com/help...

14 days ago | 0

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Answered
How can I find the sum of an array with the minimum value excluded?
A = [16 21 54 32 87 12] B = sum(A) - min(A) If A is a matrix use: A = [16 21 54; 32 87 12] B = sum(sum(A)) - min...

14 days ago | 0

Answered
i have two martices
x = [1 2; 3 4] y = [5 6; 7 8] z = [x(:) y(:)]

14 days ago | 0

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Answered
any code availabe or toolbox in MATLAB to implemente PSO?
Hi, yes there is the <https://de.mathworks.com/help/gads/particleswarm.html |*PSO function*|> from the <https://de.mathworks....

14 days ago | 0

Answered
how to write matlab bvp4c code for moving boundary surface problem?
Hi, i recommend to start simple and work step by step: # Have a read in the documentation of <https://de.mathworks.com/hel...

14 days ago | 0

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Answered
Storing .xml information in matlab
Hi, check <https://de.mathworks.com/matlabcentral/fileexchange/28518-xml2struct this@FEX> - there is also an <https://de.math...

14 days ago | 0

Answered
get computer IP problem
Hi, try: [~, result] = system('ipconfig') result: Windows-IP-Konfiguration Ethernet-Adapter LA...

14 days ago | 0

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Answered
How can I create a signal that contains the sum of two cosine waves of equal amplitude at 40 Hz and 45 Hz
fs = 1000; % Sampling rate 1000 Hz = 1 kHz t = 0:1/fs:1; % take a sample of 2 seconds with 1 kHz sampling rate f1 = 40;...

15 days ago | 1

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Answered
Create a vector by selection randomly vectors
A=[1 2 3 4 5]; B=[0 2 5 6 19]; C=[0 0 1 3 0]; D=[1 0 1 15 0]; pool = [A; B; C; D]; n = 10 % Number of vectors t...

15 days ago | 1

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Answered
Neural network training Help
Hi, i guess this question is related to the other 2 questions you asked. The basic procedure is retained as shown in <https:/...

15 days ago | 0

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Answered
Machine Learning, Forecast Wind, Forecast Irradiation, Historical Data
Hi, to start with machine learning i recommend to use the provided Apps from the Statistics and Machine Learning Toolbox. In ...

15 days ago | 1

| accepted

Answered
Help regarding use of BVP4C in solving an third order ODE.
Hi, this works: init=bvpinit(linspace(0,4,8),[0 0 0]); sol=bvp4c(@rhs_bvp,@bc_bvp,init); plot(sol.x,sol.y(1,:),...

16 days ago | 0

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Answered
how can i import data from mat file to simulink?
Hi, the content in your .mat-file has to be saved as a <https://de.mathworks.com/help/matlab/ref/timeseries.html *|timeseries...

16 days ago | 0

Answered
How to find the indices of a matrix element that is inf or NaN?
Hi, >> 81^3 ans = 531441 is the number of entries in V - you get 531439 back. That means 2 are m...

16 days ago | 1

Answered
optimization, fmincon. Help
Hi, the usage of global variables is not recommended. You missed to define the function handles Fcost1_4 ... Fcost3_4 in Fcom...

16 days ago | 0

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