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Stephan


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1,463 total contributions since 2017

Knowledge means knowing where it is written...

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- Mathematical Modelling
- Improvement of my programming skills

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Answered
Change frame rate of video file
You are fully right. First read all the frames using the read command for VideoReader. Then make a VideoWriter object and use th...

1 hour ago | 0

Answered
How to optimise two variables at once
b = 166; %inertance c = 2000; %damping value lb = [0 500]; % lower bound ub = [500 3000]; % upper bound x0 = [b, c]; %...

2 hours ago | 0

| accepted

Answered
How to find every combination of values in a cell array?
One way, using allcomb: M = {[1,2,3], [4,5,6],[7,8,9]; [10,11],[12,13],[14,15]; [16,17,18,19,20],[21,22,23,24],[25,26,27,28]}...

3 days ago | 1

| accepted

Answered
function in matlap#
https://de.mathworks.com/help/matlab/ref/function.html https://de.mathworks.com/help/matlab/matlab_prog/create-functions-in-fil...

4 days ago | 0

Answered
How to ignore negative indices or assign it to zero in a loop
It is not needed to make the elements zero - they are already, because you preallocated y with zeros: x=[1 2 -1 -3 -4] h=[0 1 ...

5 days ago | 0

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Answered
Matlab schließt sich sofort nach dem starten wieder
Hallo, in diesem Forum wird fast ausschließlich auf Englisch geschrieben - was die Chance Deiner Frage beantwortet zu werden dr...

5 days ago | 0

Answered
Create Block Toeplitz Matrix
Try: rng(123) A = eye(3); B = randi(10,3); Omega = kron(A,B) gives: Omega = 7 6 10 0 0 0 0 ...

6 days ago | 0

Answered
IF statements together with ODE
This example appears to be what you need.

14 days ago | 0

Answered
How to prepare a matrix with variables that contain a range of values?
syms c s x % Tsigma Tsigma = [c^2 s^2 2*c*s; s^2 c^2 -2*c*s; -c*s c*s c*2-s^2]; Tsigma = subs(Tsigma,[s, c],[sin(x), cos(x)...

17 days ago | 0

Answered
Cubic funtion for interpolating
https://de.mathworks.com/help/matlab/ref/polyfit.html https://de.mathworks.com/help/matlab/ref/polyval.html

17 days ago | 1

Answered
Plot multiple probability distribution function side by side
% My code is not giving me what I want. pd1 = makedist('Normal') pd2 = makedist('Normal',2,1) x = -10:.1:10; pdf_x = pdf(pd1...

17 days ago | 0

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Answered
How to solve a linear system A * X = B when B and X are matrices instead as vectors?
linsolve can handle this. From documentation (Input Arguments): "...If B is a matrix, then each column in the matrix represents...

18 days ago | 0

Answered
I need to plot "e" by function of all values of "dm" i but can't do it please help
F=2000 ; dm=[12: 5: 37]; f=0.2 ; l=2 ; Q= ((F.*dm)/2)*((l+(pi*f.*dm)/((pi.*dm)-(f*l)))) ; e= (F*l)./(2*pi.*Q); % ^ ...

18 days ago | 0

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Answered
How to calculate the area of only white part in the image
Same as in your question yesterday: regionprops will solve both problems in 1 line of code.

18 days ago | 1

Answered
Error happen when doing optimization by using "surrogateopt"
f1 is a 2x1 vector - the objective of an optimization has to be a scalar. Thats the error. You need a criterion that expresses t...

18 days ago | 0

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Answered
How to concatenate a (REAL) string vector?
A=["abcd","efghijk"; "lm", "opkq"] B = A(:,1) + A(:,2) The more general solution (independent from number of rows or columns o...

18 days ago | 0

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Answered
How to insert a cell with string into a table as variable
The solution is inside the error message: B is a cell array of strings specify names in a string array or cell array of cha...

18 days ago | 0

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Answered
how to include a 'probability' when coding.
Use this every time you want to reward by random reward = rand(1) <= 0.6 reward = rand(1) <= 0.6 reward = rand(1) <= 0.6 rew...

18 days ago | 2

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Answered
Which is the most efficient way to solve a ODE that has a parameter that changes in every period?
Are gamma and beta parameters that result from the gamma / beta functions? Or just scalar parameters? I suggest using other name...

18 days ago | 0

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Answered
How to get certain matrix columns.
A = [1 2 3 4 5 6 7 8 9 10 11 12; 13 14 15 16 17 18 19 20 21 22 23 24] A1 = reshape(A',2,[]) b = A1(:,1:3:end) b = b(:)'

19 days ago | 1

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Answered
The end operator must be used within an array index expression.
See the original question - i fixed the error. frame = read(v,[600:600:end]); will not work in this case.

19 days ago | 1

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Answered
how to remove trailing zeros after rounding a matrix?
format short A = 1.23 format shortG A = 1.23

19 days ago | 0

Answered
How to extract a frame every 10 s from the video ?
https://de.mathworks.com/help/matlab/ref/videoreader.read.html#busxibt-2 In your case the interval to take the first frame afte...

19 days ago | 1

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Answered
matrix multiple rows with the same value
repmat([20:145:600],2,1)

19 days ago | 1

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Answered
not enough input argument error
timespan=[0 15]; y0 = [0 1 0 1 0 1]; [t,y] = ode45(@repressilator,timespan,y0); figure() plot(t,y) xlabel('Time') ylabel(...

19 days ago | 0

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Answered
Help: How to add a label (cell 1 x 20) to each bar (total 20 bars) in a bar plot where the bar plot has a 1x 2 dimension?
Try: labels=reshape({'A', 'B', 'C', 'D','E', 'F', 'G', 'D','A', 'B', 'C', 'D','A', 'B',... 'C', 'D','A', 'B', 'C', 'D'}',1...

19 days ago | 0

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Answered
How to calculate the center of white part?
Look at the regionprops examples.

19 days ago | 1

Answered
Linear Interpolation code and plotting
interp1([1 6],[log(1) log(6)], 2)

20 days ago | 0

Answered
Error of sym>convertChar
syms a b c x f = str2sym('a*x^2 + b*x + c') subs(f,x,5) subs(f,[x a b c],[5 1 2 3])

20 days ago | 1

| accepted

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