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# Stephan

##### Last seen: Today
1.134 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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I need help as soon as possible
Try to work with a table to make life easier: N=1:10; a=0;b=2;alp=0.5; f=@(t,y)y-t^2+1; yexact=@(y,t)(1+t).^2-0.5*exp(t); h...

11 Tage ago | 2

Convert two vectors (x and y) to a square matrix ?
x = 0:0.01:6.28; y = sin(x); M = ones(size(x,2)); x_int = 1:size(x,2); y_int = ceil(y * size(y,2)/(abs(min(y))+abs(max(y...

13 Tage ago | 1

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Fit to find the value of an unknown parameter
Try to optimize with least squares: A=0.1; B=0.5; C=100; % Range for H lb = 0.0001; ub = 0.05; best_H = fminbnd(@(H)s...

13 Tage ago | 0

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Describing the motion of a composite body using system of differential equations
Solve numeric: syms y(t) z(t) Dy = diff(y,t); Dz = diff(z,t); eqns = [diff(y,t,2) == (29.4*cos(z)+4*Dz*Dz)*sin(z)/(1+3*sin(...

18 Tage ago | 0

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Making a Video from Images
https://de.mathworks.com/help/matlab/import_export/convert-between-image-sequences-and-video.html

19 Tage ago | 0

how to solve the non-linear equation
To solve for V as a function of Q: syms V Q D=1050; c=25; A=1000; B=1000; v=1.077; gamma =0.1; beta =0.1; eq = V*c*(1...

20 Tage ago | 0

Problem with solve function
syms s vs v1 v2 vo s R1 R2 R3 Rc1 Rc2 gm1 gm2 gm3 gmc1 gmc2 C1 C2 C3 Cc1 Cc2 k1 k2; % Nodal Analysis Equations eq1 = -gm1*vs +...

21 Tage ago | 0

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Solving three simultaneous equations for analytical solution
Keep it short and simple + use "*" for multiplication operations: syms k2 k1 Rk1 R BR s h a l2 l1 t1 t2 bh d eq(1) = k2==(BR*(...

21 Tage ago | 0

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Plotting Equation with straight line
<https://de.mathworks.com/help/matlab/ref/fplot.html |*fplot*|>

etwa ein Monat ago | 0

bvp4c error
In your case bvp5c is suitable to solve your problem, without changing the timespan: solinit = bvpinit([0,1],[0,0]); sol = bvp...

etwa ein Monat ago | 0

How can I make the wave in the negative part disappear?
More resolution for the values + logical indexing: t= linspace(0,6,5000); y=sin(pi*t); plot(t(y>=0),y(y>=0))

etwa ein Monat ago | 1

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How to convert cells within cells to double.
Due to the different lengths of all the entries you can not easily store them in a matrix, but as a column vector it will work e...

etwa ein Monat ago | 0

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How to solve Integer Linear program
Work through this examples: https://de.mathworks.com/help/optim/ug/intlinprog.html#bts3f9f-4

etwa ein Monat ago | 0

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Storing indices from a matrix
A= [ 1 2 3 -4 6 -2]' B = find(A<0) A = 1 2 3 -4 6 -2 B = 4 6

etwa ein Monat ago | 0

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how to do Shifting of text
A = "volatile uint8_T AtomcMduleCnt_Z_Pt = 7U;/* Atomic Module Count in Pack */" B = insertAfter(A,"uint8_T"," @") A = ...

etwa ein Monat ago | 0

rational curve fitting function?

etwa ein Monat ago | 0

Note that your link refers to R2019b. The example you are looking for in R2019a you find here: https://de.mathworks.com/help/re...

etwa ein Monat ago | 0

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Sort and accumulate data in a matrix
Here is an example: A = [-10 0 10 10 20 -20 30 -30 40 -50 50 -40 -10 0 0 10 20 -20 30 -30 40 -50 50 -40 40 40 40]; groups = fi...

2 Monate ago | 0

How to save the 60 value in two columns as a csv file?
Use writematrix for this beginning from R2019a. For earlier releases you can use csvwrite. If x and y are of size 60x1 why not ...

2 Monate ago | 0

How can I solve a nonlinear model using Newton Raphson ?
One way: result = fsolve(@fun,[1 1 1]) function F = fun(x) F(1) = x(1) + x(2).^2 + cos(x(3)) - 2; F(2) = x(1) + sin(x(2)) ...

2 Monate ago | 2

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How display a log space bar figure ?
% Set y-axis to log scale set(gca, 'YScale', 'log')

2 Monate ago | 0

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can anyone tell whre is the error ?
x=-2*pi:0.01:2*pi; y=exp(x); z=sqrt(exp(-x)); figure(3) p=plot(x,y,'r',x,z,'b'); p(1).LineWidth = 2; p(2).LineWidth ...

3 Monate ago | 0

How to replace the empty cells in a cell array by a 4-bits string?
load('Key.mat'); Key1 = Key(:); Key1 = reshape(replace(string(char(Key1{:}))," ","0000"),size(Key,1),size(Key,2)); results...

3 Monate ago | 0

How to generate a symmetric Toeplitz matrix?
>> toeplitz([-pi 0 pi]) ans = -3.1416 0 3.1416 0 -3.1416 0 3.1416 0 -3.14...

3 Monate ago | 4

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"syms", "sym", and "mupad" functions cause MATLAB to freeze
R2017b had this bug, but it was fixed in update 7 and following. Try to install the latest update for your release - see Step 2:...

3 Monate ago | 0

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...

4 Monate ago | 0

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

4 Monate ago | 0

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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) + ...

4 Monate ago | 0