Community Profile # Torsten

Last seen: Today Active since 2013

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Use pdepe to solve an ode
So your equation is not a PDE, but a simple ODE. Either you try to artificially set du/dx = 0 at both ends and see whether the...

3 giorni ago | 0

Projected curve lengths (XY,XZ,YZ) of 3D arcs
Then just set the coordinate of the plane you project on to 0 and calculate the arc length of the resulting projected curve. An...

3 giorni ago | 0

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Solving a system of PDE using pdepe
The error is solved, but I think the boundary conditions at the right end can't be set within pdepe. The condition set at the m...

3 giorni ago | 1

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optimization toolbox with fmincon
If you want to admit x,y and z to be complex-valued, you also have to change your objective function to be real-valued for compl...

4 giorni ago | 0

How do I find the index of the first element equal to 0 for each row of a matrix in a fast way
[~,idx] = max(M==0,[],2) or idx = arrayfun(@(k)find(M(k,:)==0,1),1:size(M,1))

4 giorni ago | 0

Spline coordinates from spap2
x = -2:.2:2; y=-1:.25:1; [xx, yy] = ndgrid(x,y); z = exp(-(xx.^2+yy.^2)); sp = spap2({augknt([-2:2],3),2},[3 4],{x,y},z)...

4 giorni ago | 0

How can the lqr function in matlab be modified so that the 2*x'Nu term in the cost function J be replaced with a scalar value?
I wonder why the integral should be finite if you replace 2*x'*N*u by a fixed scalar value. This scalar value must definitely be...

4 giorni ago | 0

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solve quadratic equation with matrix input variable
syms P N =2000:-50:50; guess = 2; for i=1:numel(N) n = N(i); eqn=((((1.3+(((17.5).*P)./(P+n./20))).^2)+((0.036.*P)....

4 giorni ago | 0

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estimation of probability density function
help ksdensity

4 giorni ago | 0

Function value and YDATA sizes are not equal using lsqcurvefit
The integrator was not able to integrate your system of differential equations. So there was no or only an incomplete solution r...

4 giorni ago | 0

Solving system of 3 non-linear equation with dynamic equality output
syms x1 x2 x3 t A eqns = [ x1 == t*(10*abs((18*x2)/125 - (24*x1)/125 + 111/50)^2*sign((18*x2)/125 - (24*x1)/125 + 111/50) ...

5 giorni ago | 0

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Error in function interp1: Sample points must be unique.
You can use unique() to get rid of duplicate sample points. It will also sort them.

5 giorni ago | 0

Solving a System Consisting of PDEs & ODEs using Method of lines
What's wrong with the results ? The fact that Ca becomes negative ? L = 5; % length of reactor v = linspace(0,L,100).'; % di...

5 giorni ago | 0

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Error using integral; First input argument must be a function handle.
function z= continum(var,energy) z = integral(@(x)cont(var,x),2.39,inf); end

5 giorni ago | 0

Summing anonymous functions in a for loop: adding penalty terms for optimization
basefun returns a vector of size (8x1) . Now to each component of this vector you add the sum of the following scalar values la...

5 giorni ago | 0

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Does MATLAB have a feature to show step-by-step solution?
m = 5; B0 = 1; B = fsolve(@(B)fun(B,m),B0) fun(B,m) function res = fun(B,m) B sum1 = 0.0; sum2 = 0.0; for j=0:m-1 ...

6 giorni ago | 0

Need help to program the hypergeom function
https://de.mathworks.com/help/symbolic/hypergeom.html

6 giorni ago | 0

Create random numbers inside a specific plane in xy plane
rng("default") x = [2;8]; y = [1;2]; R = rand(2,400) S = [x(1);y(1)]+[[x(2)-x(1);0],[0;y(2)-y(1)]]*R

6 giorni ago | 0

How do i write CO2 emission constraint?
Every M_CO2^t will be a solution variable x(i) in your optimization. So setting the constraints -(x(i)-x(i-1)) <= 0 for i <=...

6 giorni ago | 0

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Finding the coordinates of a point given the gradient, distance and one set of coordinates
m = 0.4; x1 = 10; y1 = 4; s = 15; z = [x1 y1] + s/sqrt(1+m^2)*[1 m]; x2 = z(1) y2 = z(2)

7 giorni ago | 0

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Model of two differential equations of RLC circuit (Simulink)
Solve the system of differential equations dI1/dt = i1, I1(0) = 0 dI3/dt = i3, I3(0) = 0 L*di1/dt = U - R*i1 - 1/c * I1 - 1/c...

7 giorni ago | 0

Curve fit app displays wrong curve
pc = [ 1.8513e+03 3.6393e+03 3.7146e+03 3.7914e+03 3.8699e+03 3.9500e+03 4.0317e+03 4.1151e...

7 giorni ago | 0

how to set a range of data instead of percentile?
https://de.mathworks.com/help/matlab/ref/isoutlier.html

8 giorni ago | 0

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unable to use solve or fsolve for linear system
Seems your equations are not independent. syms R1 R2 R3 R4 COM = [-6,0,10]; r1 = [-54.2,-27.5,-16.4]; r2 = [-54.2,27.5,-16.4...

8 giorni ago | 0

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Implementing implicit method for system of ODEs
n = 50; % number of time steps t0 = 0; % initial time T = 2*pi; % final time dt = (T-t0)/n; % size of timestep y0 = [1;0]; %...

8 giorni ago | 0

reflection of a curve with respect to a plane
x = -1:0.2:10; y = x.^2 + 2; z = zeros(size(x)); P = [2 2 2]; V = [0 0 1]; d = (P.' - [x;y;z]).' * V.'; Ps = [x;y;z] + 2*V...

8 giorni ago | 0

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where is the error in my code?
V1 = @(r,w) -acosh(10*(w/(1600*r + 21))^(1/2))/20000000000; V2 = @(r,w) acosh(10*(w/(1600*r + 21))^(1/2))/20000000000; % Defin...

9 giorni ago | 0

I have three coupled differential equation and need help to solve them
You have a linear system of equations in dx/dt, dy/dt and dz/dt. Solve it for these variables. Then you can write your system e...

9 giorni ago | 0