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Stephan


1 108 total contributions since 2017

Knowledge means knowing where it is written...

Interested in:
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Answered
How to use VPA (variable precision arithmetic) in calculating HH band via dwt on an image?
You can not do this. dwt2 accepts only double as input and outputs double. vpa works on symbolic variables and returns a symboli...

2 jours ago | 0

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Answered
String to Categorical array
x = [zeros(1,120), ones(1,240)]; res = categorical(x, [0, 1], {'Z', 'O'});

2 jours ago | 0

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Answered
Reducing 2nd order ODE into coupled ODE. Solve using Euler Method and graph.
tspan = [0 5]; % time span to integrate y0 = [3 0]; % initial conditions %Start of Euler Method syms y(t) E = diff(y,2) + ...

2 jours ago | 0

Answered
How to convert cell array to double?
c = {[1 2],[2 3]} s = cell2mat(c) s = unique(s)

2 jours ago | 0

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Answered
hi,i am getting error as not enough input arguments,while i run the below code....?? please let me know that?(the error is in second line of code)
Works fine for me, if called with *_2_* input arguments: res = trio(3,4) function x=trio(m,n) x=rand([3*m n]); ...

2 jours ago | 0

Answered
How to solve coupled (differential) equations of motion using matlab?
Whta is the problem? There is an analytical solution (here assumed that vx0 and vz0 are equal to 1): syms w b g m x(t) y(t) z(t...

3 jours ago | 0

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Answered
Undefined operator '/' for input arguments of type 'function_handle'
b=400; %mm d=500; %mm Asv = [3000 5000 3000 5000]; %mm^2 fckv = [30 30 90 90]; %Mpa num_fckv = numel(fckv); fsolve_opt...

3 jours ago | 0

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Answered
Can't plot function
x = linspace(0,10); y = sqrt(1+x.^2)./sqrt(x.^4-x.^2+1); plot(x,y)

3 jours ago | 1

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Answered
Fit Powerlaw to Data
https://de.mathworks.com/help/curvefit/custom-nonlinear-models.html

5 jours ago | 0

Answered
Numerical Solution for a System of Three ODEs with Different Constant for Each Time Element
Use interp1 for this. Here is an example: https://de.mathworks.com/matlabcentral/answers/487412-using-ode45-to-solve-differenti...

6 jours ago | 0

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Answered
Text file manipulation, find specific lines, find there a string and replace the specific line with new content
There is a bunch of possibilities to manipulate strings: https://de.mathworks.com/help/matlab/ref/extractafter.html https://de...

6 jours ago | 0

Answered
Fitting an equation to a Sine Function with NonLinearModel.fit
"...I already tried using the "cftool" function in matlab but it did not have the equation I need...." Did you notice that yo...

6 jours ago | 0

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Answered
How to replace last 3 digits in a floating point number by another 3 digits
format long x = -3.141592653589793; a = 287; x_new = sprintf('%.15f',x); x_new(end-2:end) = (sprintf('%d',a)); x_new = st...

6 jours ago | 0

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Answered
I am trying to use ODE45, but I keep getting an error with myfcn saying I don't have enough inputs?
There are at least 4 problems in your code: 1. Split your main code and your ode function: tspan = [0 10]; f0 = [0 0]; ...

6 jours ago | 1

Answered
Having trouble with ODE45 and a System of Ordinary Differential Equations
For every equation you have to input an initial condition. You have 8 but only give 2 initial conditions to ode45. Also your ...

7 jours ago | 0

Answered
Is there a function to turn ?x2 matrix of coordinates of vertices of a polygon into a ?x4 matrix of coordinates of line segments of that polygon?
Yes, circshift will do the job: A = [2, 4; 5, 6; 6, 6; 8,5] B = [2, 4, 5, 6; 5, 6, 6, 6; 6, 6, 8, 5; 8, 5, 2, 4] % The sol...

7 jours ago | 0

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Answered
could anyone help me to display the values in the matrix which are greater than the average value for the following code
B, C and D are not needed, if you use the inbuilt function mean: A=[3.3734 5.1245 4.3729 2.8406 6.5283 4.8144 ...

7 jours ago | 0

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Answered
How can calcuate the lines of code efficiently?
Yes, you can if you avoid using a loop and vectorize your code - see here: tic %%%code nx=512; ny=nx; dx=1; dy=dx; format...

7 jours ago | 1

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Answered
how can i differentiate a constant in simulink?
You already have done everything exactly correct - Simulink also did what is correct. What is the derivative of y(t)=3 with resp...

7 jours ago | 0

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Answered
Eigenvalues and Eigenvectors of Symbolic Matrix
syms E t H = [E -t -t -t -t 0 0 0 0;-t E 0 0 0 -t -t 0 0;-t 0 E 0 0 0 0 -t -t;... -t 0 0 E 0 -t 0 -t 0; -t 0 0 0 E 0 -t 0...

7 jours ago | 0

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Answered
what is wrong with my script
clear all for loop_index = 1:2 x = input('Input number to convert'); units = input('Input the units to convert from','s...

7 jours ago | 1

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Answered
Any trick to name a variable with decimal number?
No, it is simply not allowed in Matlab. No way, no trick: https://de.mathworks.com/help/matlab/matlab_prog/variable-names.html#...

8 jours ago | 0

Answered
PULL OUT A SPECIFIC WORD FROM A LONG STRING
You might want to start reading here: https://de.mathworks.com/help/matlab/matlab_prog/searching-and-replacing.html

8 jours ago | 1

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Answered
How do I create a for loop to extract data from table?
No loop is needed: A = unstack(ReactionTime,'RESPONSE_TIME_ehmi','videostring') since you have invalid names for you video fil...

8 jours ago | 0

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Answered
complement of an image
I = fliplr(imread('cameraman.tif')); I1 = triu((I),1); I2 = tril(imcomplement(I)); I_res = fliplr(I1+I2); imshow(I_res) B...

8 jours ago | 1

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Answered
Trapz gives "Second and third argument must either be variables or a variable and a nonnegative integer specifying the number of differentiations."
syms x f_scalar = @(x) 5*x^2+3*x-4; g_scalar = @(x) -4*x^2+6*x+5; f = @(vec) arrayfun(f_scalar,vec); g = @(vec) arrayfun(g_sca...

8 jours ago | 0

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Answered
Problem with input of ode113
I_1= pi^2; I_2= -2*pi^2; params.tau= 10; g= 0; V_1= -65; V_2= -65; state= [V_1;V_2]; I= [I_1;I_2]; options = odeset('ab...

9 jours ago | 0

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Answered
How to define discrete variables in GA (genetic algorithm)
https://de.mathworks.com/matlabcentral/answers/401059-setup-discrete-values-for-decision-variables-in-optimization-problems

9 jours ago | 0

Answered
Surrogate search with integer parameters
|*intcon*| was introduced to surrogateopt in R2019b. <https://de.mathworks.com/help/gads/release-notes.html>

9 jours ago | 0

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Answered
Accessing value in a cell
Edited because of the comments: a = {'1,65,4,5'} b = str2num(a{:}) b(2)

10 jours ago | 1

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