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Stephan


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1 510 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
Creation of a black and white image
image=zeros(512,512); image(206:305,206:305)=255; imshow(image)

5 jours ago | 0

| accepted

Answered
From symbolic to numerical results for quadratic equation
You could use symbolic functions: syms y(a,b,x) y(a,b,x) = a*x^2 - b*x % Calculate values for a=1, b=2 and x in a range from...

5 jours ago | 0

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Answered
Create an equally spaced vector when taking the sine of another vector
p_inv = linspace(-1,1,25); theta = asin(p_inv); p = sin(theta); diff(p) % Is p equally spaced? scatter(p,theta)

5 jours ago | 0

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Answered
Comparing 2 frames from video
Try: function [P,MSE]=Untitled(original_img,stego_img) original_img=double(original_img); stego_img=double(stego_img); if ...

5 jours ago | 0

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Answered
I am unable to find pv array in 2014b please help me to find it.
PV Array was introduced with R2015a - you can not find it in R2014b - see the link. Are you sure your friends version is 2014a? ...

7 jours ago | 0

Answered
HOW TO SOLVE 2 EQUATION ODE USING ODE45 IN MATLAB?
f = @(t,y) [0.303*y(1)-0.557*y(1).^2+0.260*y(2).*y(1);... 0.0345*y(2)-1.18e-7*y(2).^2+3.55e-14*y(1).*y(2)]; Y0 = [0.0718,0...

14 jours ago | 0

Answered
How to plot parametric curve
https://de.mathworks.com/help/matlab/ref/fplot.html#bu6xntl-12

19 jours ago | 0

Answered
Get mean and stdev from all values
Use a table and then use findgroups combined with splitappy. This will allow you to solve the problem with a few lines of code. ...

19 jours ago | 0

Answered
Vectors must be the same length.
Change line 1: t=linspace(0,1,256); fc=60; fm=15; ac=1; am=1; wc=2*pi*fc; wm=2*pi*fm; mt=am*cos(wm*t); m_ac=ac*cos(wc...

20 jours ago | 0

Answered
hello everyone. How to divide a group of points named data into two parts, dataA and dataB, as shown in the figure. Thank you very much.
% divide data idx = clusterdata(data,2); dataA = data(idx==2,:); dataB = data(idx==1,:); % plot results scatter(dataA(:,1...

20 jours ago | 0

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Answered
element wise operation column matrix
Temp_data= [20;27;29;33;40] Case_1 = Temp_data - Temp_data(1) Case_2 = diff(Temp_data)

28 jours ago | 0

Answered
Return the number of rows of an array
A = [10 20 30 40 50 60 70 80 90 100] B = A(A<50)

28 jours ago | 0

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Answered
Getting wrong sine wave for frequency 10KHz
Think about your sampling rate: f = 10000; t = 0:1/(25*f):0.002; plot(t,sin(2*pi*f.*t))

28 jours ago | 0

Answered
split matrix into two based on column values
A = [ 1 2 1.4; 1 3 1.4; 2 5 1.4; 1 5 81; 3 4 1.4; 5 4 81] A1 = A(A(:,end)>80,:) A2 = A(A(:,end)<=80,:)

28 jours ago | 0

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Answered
How to change the direction of x axis.
A = imread('ngc6543a.jpg'); imshow(A) B = fliplr(A); imshow(B)

environ un mois ago | 1

Answered
Why can't a circle be detected in such an obvious image?
Use a range for radius input argument such as: [centers1,radii1] = imfindcircles(img,[50 200],'Sensitivity',0.85,'ObjectPolarit...

environ un mois ago | 0

Answered
Help with solving a system of equations
Please check carefully if this is correct and if it is what you need: %% Case 1: N = 19 % clc % clear % b = 6; % Vinf = 1...

environ un mois ago | 1

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Answered
How to calculate NDI Index
NDI_new = uint8(rescale(NDI, 0, 255));

environ un mois ago | 0

Answered
Audioread Function Error.
Re-Install your Matlab version if you are not able to undelete the file. There is no other legal way to help you, because it is ...

environ un mois ago | 0

Answered
How to set Assumptions for function handle?
See fimplicit3 example here and use interval argument: f = @(x,y,z)x.^2+y.^2+z.^2-1; fimplicit3(f, [-1, 1, -1, 1, 0, 1])

environ un mois ago | 0

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Answered
Loop function takes too long. How can I reduce the processing time?
Yes, diff in as inbuilt and vectrorized function to get what you want. Run this command on a vector input will give you all the ...

environ un mois ago | 0

Answered
Splitting code into groups
Note that the run button will run all your code in one, while the other buttons will run you code section wise and go / go not t...

environ un mois ago | 0

Answered
Solution to a simple equation
use isolate instead of solve: clear all; close all; syms R L C omega eqn=1 - 2*C*L*omega^2 + C^2*R^2*omega^2 + C^2*L^2*omega^...

environ un mois ago | 0

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Answered
how to make a function of this system
syms a b y1(t) y2(t) ode(1,1) = diff(y1,t,2) == a*y2 - cos(diff(y1,t)); ode(2,1) = diff(y2,t) == b*y1 + cos(t) [V,S] = od...

environ un mois ago | 1

Answered
error with plotting graph
Since theta is a vector you need to perform elementwise multiplication: a = 13; c = 17; k = 2*pi/3; theta = 0:0.0001:2*pi; ...

environ un mois ago | 1

Answered
Getting error with the code in ode45 function
t=[0 5]; inity = 1; [t,y]=ode45(@f, t, inity); plot(t,y) function dy = f(~,y) % y=[9,100]; dont overwrite y D=0.00000001; ...

environ un mois ago | 0

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Answered
How can I plot the Temperature distribution in this code.
Play arround with slice: % LBM 3D - D3Q15 Heat Diffusion in a Plate % Problem - 5.10 clc clear variables close all alpha =...

environ un mois ago | 1

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Answered
How to multiply a matrix to another cell matrix
Use cellfun: A = magic(3) C = {rand(3,4); rand(3,4); rand(3,4); rand(3,4); rand(3,4)} result = cellfun(@(x)mtimes(A,x),C,'Uni...

environ un mois ago | 1

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Answered
Why do the ode45 solver is not running in my code?
Your problem appears to be stiff - use ode15s instead: clear; clc; a = 1; %alpha p = 7.5; %rho b = 4; %beta g = 16; %gamma ...

environ un mois ago | 0

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Answered
i'm getting this error "Unable to perform assignment because the left and right sides have a different number of elements"
Problem 1 h returns more than one solution which produces the error because the result of xa1(i+1)=I2(i)+h*S2(1) with h bein...

environ un mois ago | 1

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