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Torsten


Last seen: Today Actif depuis 2013

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Where can I learn how to do regression in Matlab
First learn how to approach your problem from the statistical side, then look how to implement this theoretical approach in MATL...

environ 4 heures il y a | 0

A répondu
Trying to use Newton Raphson Method to solve circuit design
w = 1; T = 2*pi/w; tn = 0:T/40:T; I = 1e-15; Vt = 25.9e-3; Vo = 10; V1 = 6; V2 = 6; R = 50e3; x0 = [0.7;0.7]; e_d = 1...

environ 8 heures il y a | 1

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A répondu
rror using odearguments @(T,Y)ODE_LR(T,Y,KF_L,KB_1) returns a vector of length 2, but the length of initial conditions vector is 10002. The vector returned by @(T,Y)ODE_LR(T,Y
Use Non_Active_Receptor_concentration0 = 100; Active_Receptor_concentration0 = 0; instead of Non_Active_Receptor_concentrat...

environ 14 heures il y a | 0

A répondu
plot the function which is dependent on x, y and z with x, y and z on three axis.
You can plot the function on slices (i.e. 2d-objects (e.g. planes)) through the volume of interest. Of course a full plot over ...

environ 14 heures il y a | 0

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Left and Right side have different elements
Replace t by t(i) in the loop.

1 jour il y a | 0

A répondu
Getting integrand error from triple integral code code
f must return a vector of ones of the same size as the inputs x, y or z (which all have the same sizes). Thus replace f = @(x,...

2 jours il y a | 1

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need to compile outputs from for loop into array
In most cases, outputarray = zeros(1,nnz(mod(yeararray,4)==0)) will work.

2 jours il y a | 0

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Error ---> Brace indexing is not supported for variables of this type.
clc clear g = 9.81; L = 0.1; m = 0.5; zeta = 2; x0 = 0.25; v0 = 0; tspan = [0 10]; step_sizes = [0.1, 0.05, 0.025...

2 jours il y a | 0

A répondu
error lsqcurvefit for integrate function
Replace % Define the model function (vectorized for efficiency) function y = model(theta, x) k0 = theta(1); E0 = theta(2...

3 jours il y a | 0

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How to set Drichlet and Neumann boundary conditions for a set of ode in BVP solver
Is there a possibility that I can set three boundaries (mix between Drichlet and Neumann boundary) for a set of two ODE's? No....

3 jours il y a | 0

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Trying to determine roots of this polynomial (Det)
k = [1750 -750 0; -750 1250 -500; 0 -500 500]; m = [75 0 0; 0 75 0; 0 0 50]; eig(k,m)

3 jours il y a | 1

A répondu
Civil engineering coding problem ( I dont know where the problem in my code is and how to solve it, thanks in advance )
"coord" has only three rows, but you try to access coord(4,1) and coord(4,2) which do not exist (see above).

3 jours il y a | 0

A répondu
Why I am getting this error message? How to fix it?
Maybe you mean this function: function v = vec(m) %Helper function to turn a matrix of any size into a column vector using (:)...

3 jours il y a | 1

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How to draw a three-dimensional function image corresponding to the analytic expression of a given piecewise function image
f = @(x,y)(4*y-4*x.*y-2*y.^2).*(y<x).*(x+y<1)+2*(1-x).^2.*(y<x).*(x+y>=1)+(4*y-4*y.^2-2*x.^2).*(y>=x).*(x+y<1)+(2-4*x+4*x.*y-2*y...

3 jours il y a | 0

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Generalized Orr Sommerfield error returned in Eigs Function
I suggest you comment out the command W0 = @(x) lambertw(0,x); like %W0 = @(x) lambertw(0,x); include a function for W0 as ...

4 jours il y a | 0

A répondu
How can i solve this problem' when i am running, this message appears: Failure in initial objective function evaluation. FMINUNC cannot continue.
Call your function in which you define the sum of differences squared between real and modelled data for the initial values of y...

4 jours il y a | 1

| A accepté

A répondu
hypergeom function, no output
The hypergeometric function has convergence criteria: Converges if p ≤ q and |z| < ∞. Converges if p = q + 1 and |z| < 1. For ...

4 jours il y a | 1

| A accepté

A répondu
How to plot a simple wave equation using method of lines?
n = 100; m = 100; tf = 1; dx = 1/n; x = linspace(0,1,n+1)'; tspan = linspace(0,tf,m+1); y0 = [sin(2*pi*x);zeros(n+1,1)]; %[t...

4 jours il y a | 0

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Analytical solution of 1-D transient heat transfer
I'd compare with the solution from "pdepe": m = 1; Ri = 0.05; nd = 20; r = linspace(0,Ri,nd); t = [0 100 600 1800 3600 5000...

5 jours il y a | 0

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Solve Nonlinear ODE Symbolically
This is a nonlinear system of ODEs. An analytical solution with symbolic math is not possible. The only way to solve it is nume...

6 jours il y a | 1

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Triple intergral for the array valued function
N = cell(2,3); N{1,1} =@(x,y,z) x.^2+y.^2+z.^2; N{1,2} =@(x,y,z) x.^2+y.^2+z.^2; N{1,3} =@(x,y,z) x.^2; N{2,1} =@(x,y,z) y....

6 jours il y a | 0

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does "generalized Neumann" boundary condition include actual Neumann boundary condition?
Is there maybe a workaround (like change of variables) to solve these problems? No. All Neumann boundary conditions are related...

7 jours il y a | 0

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Graphing 1D Diffusion in 2 Compartments - Possible Issue with ODE solver
In my opinion, you have the following conditions at the interface x = h_D: (1) D_D*dC_D/dx = D_R*dC_R/dx (2) C_R = phi*C_D (or...

7 jours il y a | 0

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I want to optimize an ODE system of equations with constraints
I ran your code with k in the order of 0.1,1 and 10, but it seems the k-values have amost no influence on the result of the inte...

7 jours il y a | 0

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Solving edge-value problems with unknown intervals
Define a dimensionless variable x' = x/l1 and transform your equation to the form dY/dx' = ... which has to be solved in [0 1]. ...

7 jours il y a | 1

A répondu
How to calculate a composite triple integral with exponential function?
Setting l, r and s to zero will cause problems because you divide by these variables. But also changing integral2(@(s,l)array...

8 jours il y a | 0

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Error using lsqncommon Lower and upper bounds not supported with complex-valued initial function or Jacobian evaluation.
If you use "fmincon" and (f(x,xdata)-ydata)' * (f(x,xdata)-ydata) as objective function, complex numbers don't matter because th...

8 jours il y a | 0

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Solve a complex differential equations system
The main problem with your equations is that they involve a term that has to be evaluated at a boundary point. Otherwise, you co...

9 jours il y a | 0

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an ode with arguements
You have to define your vector of solution variables as y(1) = f, y(2) = f', y(3) = f'', y(4) = T, y(5) = T' and your function...

9 jours il y a | 0

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How to invert a square matrix using Gaussian elimination
The newton update is x_(n+1) = x_n - Df^(-1)*f, not x_(n+1) = x_n + Df^(-1)*f. But you should not explicitly compute the ...

9 jours il y a | 1

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