Community Profile # Torsten

Last seen: Today Active since 2013

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How can I fix "Error in sym/subsref (line 898) R_tilde = builtin('subsref',L_tilde,Idx); ?
KgQ(indiciesQ,indiciesQ) = KgQ(indiciesQ,indiciesQ) + subs(KeQ,[x1Q x2Q x3Q], [xQ(i*2-1) xQ(i*2) xQ(i*2+1)]); % Ke into Kg contr...

11 hours ago | 0

Solving 3 equations with 3 unknowns
No problem. A = [2*sqrt(44.4) 0 0; 2*sqrt(34) 2*sqrt(3.92) 2*sqrt(57.4);2*sqrt(21.8) 2*sqrt(25.5) 2*sqrt(25.5)]; b = [52.11;52...

12 hours ago | 1

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If I had the derivative of an equation and had data points how would I plot them
d = @(x)1 - sin(x)./(2*sqrt(x)) - sqrt(x).*cos(x); x = [1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0]; plot(x,d(x))

13 hours ago | 0

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All combinations of the sum of 2 columns
a = [29;31;34].' ; b = [31;31;31] ; x = b-a xmax = max(x(:))

13 hours ago | 1

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secant method exceeds the number of array
x(i+2)=x(i)-(fun(x(i))*((x(i+1)-x(i))/(fun(x(i+1))-fun(x(i))))); For i = 1, the evaluation of the right-hand side needs x(1) an...

14 hours ago | 0

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How to create a Fourier series using for loops
k = 1:14; x = (-2:0.01:2).'; f = 0.5 + sum(2./(k.^2*pi^2).*((-1).^k-1).*cos(pi*k.*x/2) + 2./(k*pi).*(-1).^(k+1).*sin(pi*k.*x/2...

19 hours ago | 0

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Problem solving exponential equation
Your parantheses are unbalanced. After correcting it, the below code should work. syms t eqn = 1000/(exp(log(4) - t/40) + 1 ==...

21 hours ago | 0

How to quickly identify a list of nearby stations?
https://de.mathworks.com/help/stats/pdist.html And for your double loop, you should replace for i=1:m2 for j=1:m2 by fo...

21 hours ago | 0

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need a for loop that displays value at each point of x.
But I already gave you the formulae how to code "cumtrapz": 0 = ctrapz(1) [f(x0)+f(x1)]/2 * (x1-x0) = ctrapz(2) [f(x0)+f(x1)]...

22 hours ago | 0

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Putting togethor constraints for fmincon
The conditions defined under "ineqconstraint" have to be put into the matrix A and the vector b of "fmincon".

1 day ago | 0

'corrcoef' doesn't return a matrix as it should, but I always get 1?
for i=1:numel(time) coefR{i} = corrcoef((res2(i,:)).',(res3(i,:)).'); end

1 day ago | 0

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plotting functions from book
c = 1; k = 1.2:0.4:2.8; u = (linspace(0,2.4,100)).'; f = (k/c).*(u/c).^(k-1).*exp(-(u/c).^(k)); plot(u,f)

1 day ago | 0

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How to fill just such successive elements in row of matrix?
A = [ 0 50 0 0 0 0 0 50 0 0 0 0 50 0 0 0 0 0 50 0]; S = linspace(1,4...

1 day ago | 0

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Solving Double integral equations
u_0 = 1.25663706*1e-6; % permeability of free space L = 12.4; % Axial distance between rotor back plates p =8; % Number of p...

1 day ago | 0

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2nd 3rd derivatives
x = [-2:0.01:1]; y = exp(-3.*x); dydx = diff(y)./diff(x); d2ydx2 = diff(dydx)./diff((x(1:end-1)+x(2:end))/2); d3ydx3 = diff(...

1 day ago | 0

how can i sum the 'y' above in the picture i have polt ?
x = -2:0.001:2; y = 1.8*exp(-x.^2); plot(x,y) sum(y)

1 day ago | 0

How do I find the eigenvalues and vectors of an equation not of form (A*x = b*x)?
Multiply be inv(M) and use eig as lambda = eig(inv(M)*K)

1 day ago | 0

Help with Graphing Difference Equations
syms x n a b f = x^2-5*x+6; xsol = solve(f==0); y = a*xsol(1)^n + b*xsol(2)^n csol = solve([subs(y,n,0)==2,subs(y,n,1)==5],[...

1 day ago | 0

How to calculate the number of values in a Gaussian distribution greater than one standard deviation?
I want to calculate the number of values greater than one standard deviation. Maybe you mean one standard deviation apart from ...

2 days ago | 0

what the difference between the phase and arctan?
phase(z) = atan2(imag(z),real(z)) Read the documentation for atan2 to find the differences to the usual atan function: https:/...

2 days ago | 0

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Running for loop on an equation
S = [1/2, 1/3, 1/2, 1/3, 1/3, 1/2; 1/2, 0, 0, 0, 0, 0; 0, 1/3, 1/2, 0, 0, 0; 0, 0, 0, 0, 1/3, 0; 0, 1/3, 0, ...

2 days ago | 1

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Why am I not getting the m array?
yinter is not a function. So use "plot" instead of "fplot" (whatever abscissa data you might want to choose). Not that yinter(3...

2 days ago | 0

undefined function 'piecewise' for input arguments of type 'double'.
syms x y = piecewise(x <= 1, ((-2.*(x.^2))+9.*x-7), x > 1, ((10.*sqrt(x))+3)); fplot (x,y,[-5 5])

2 days ago | 1

Graphing partial sums of harmonic fourier series
x = (linspace(-2,4,200)).'; n = 1:5; f = 1 - exp(-1) + 2*sum((1-(-1).^n*exp(-1))./(1+n.^2*pi^2).*cos(n.*pi.*x),2); plot(x,f) ...

2 days ago | 0

Help using fmincon to find the 2 support locations (x1,x2) that minimize maximum bending moment
Don't know if the bending moment is correctly implemented. From how I naively interpreted the problem, x1 and x2 should lie symm...

2 days ago | 0

Resultant vector from three different location and normal vector of a plane
v1 = [0.000326 -0.00018 -0.00017 ]; v2 = [0.000365 -0.00016 -0.00017 ]; v3 = [-0.00015 -0.00018 -0.00039 ]; % compute r...

3 days ago | 2

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Finding the function of the supremum
sup-norm is a theoretical concept. There is no such function in MATLAB to calculate it for a general function. In the case abo...

3 days ago | 1

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How to generate an exponential random variable parameter 1?
https://de.mathworks.com/help/stats/exprnd.html

4 days ago | 0