Torsten

Last seen: Today | Active since 2013

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Answered
Different outputs of ode solvers inside for loop
This code gives reproducible results; I don't know exactly why your code didn't work. matrix=zeros(90,2); %Model Trace; t...

32 minutes ago | 0

Answered
Issue with iterative code
f1 = 1; f2 = 1; f3 = 1; n = 10; f = sequence(n,f1,f2,f3) function f = sequence(n,f1,f2,f3) if n < 4 disp('Choose b...

2 hours ago | 1

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May I know the default tolerance of the ode45?
odeset

3 hours ago | 0

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How to get the discriminant for symbolic quadractice equation?
I guess you mean d = b^2-4*a*c if the polynomial is given by p(x)=a*x^2+b*x+c. So the a and b in the discriminant have nothing t...

3 hours ago | 0

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MATLAB CODE of an equation including Bessel's function
Here is a very similar problem solved: https://de.mathworks.com/matlabcentral/answers/1777535-infinite-sum-with-bessel-s-functi...

17 hours ago | 0

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Answered
plot function of two variables as one variable
%% initialization clear clc close all %% Model parameters global k1 eta1 alpha3 gamma1 d N Phi xi h A B C G k1 = 6*10^(-1...

1 day ago | 0

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Answered
I want to do a stop condition in ode45 that he demands dx=0
AnonFun=@(t,x)(5*x-1*x^2); Opt=odeset("Events",@(t,x)myEvent(t,x,AnonFun)); [t,x]=ode45(AnonFun,[0,5],1,Opt); plot(t,x) func...

1 day ago | 0

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Double integration of an array function
"integral2" has no "ArrayValued" option - only "integral" has. But since the function comes from a "MatlabFunction" command, I ...

1 day ago | 0

Answered
T is not defined, dont know how to fix
After deleting the @ before ode23t, the code with @locO works for me. %ODEs n0=[0 0 0]; % Initial conditions options = odes...

2 days ago | 0

Answered
How to optimise the computation of multiple integral for a specific integrand?
Precalculate q over the hypercube on a predefined regular mesh and use "trapz" dimensionwise. Look at the example "Multiple nu...

2 days ago | 1

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substitution in symbolic.
syms s w assume(w,'real') f = s + s^2; fs = subs(f,s,1i*w); fs_real = real(fs) fs_imag = imag(fs)

2 days ago | 1

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Fit chi distribution to measurement data
Square your measurement data, and you can fit them against a chi-squared distribution.

2 days ago | 0

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Answered
Calculating and plotting conditional distribution.
You mean this lambda = 0.3; p_bar = 1; p_tilda = (1 - lambda)/(1 + lambda); S = 0:0.01:p_tilda; n = 1000000; icount = 0; ...

3 days ago | 1

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Answered
odeEvent doesn't terminate the integration process?
The functions you can prescribe as "value" should be continous. Using logicals leads to step functions that are not appropriate ...

3 days ago | 0

Answered
Giving a rectangular pulse in ode45
I can't evaluate the equations and initial conditions you use. This is what the solver returns - slight over-and undershooting. ...

3 days ago | 0

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Answered
Giving a rectangular pulse in ode45
time=linspace(0,20,300); is wrong. You must concatenate the t-vectors returned from ode45 in the three calls in the same way ...

3 days ago | 0

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Calculating roots of an equation in Matlab.
Change syms theta a to syms theta

3 days ago | 0

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how can i create Bernoulli random variable of a given probability
p = 0.2; n = 20000; A = binornd(ones(n,1),p) p_num = sum(A)/n B = 1 - A one_minus_p_num = sum(B)/n

3 days ago | 0

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Answered
Optimization: Reuse calculations from objective function in nonlinear constraints function
https://de.mathworks.com/help/optim/ug/objective-and-nonlinear-constraints-in-the-same-function.html

3 days ago | 2

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Answered
How apply the conformal mapping? (circle to rectangular)
https://de.mathworks.com/matlabcentral/fileexchange/67117-rectangular-conformal-map

4 days ago | 1

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I'm having trouble plotting the temperature field for a thin plate with border temperatures known.
Write a function function T = Temp(x,y) T = ...; end in which you calculate the value of the infinite sum for x-y coordin...

4 days ago | 1

Answered
simultaneously, fitting two functions with two databases
I think you will have to work on the representation of f1 and f2 without the imaginary unit: c10 = 3.0; c210 = 1.0; c220 = -1...

4 days ago | 0

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Answered
Intersection of two curves
Do you see a point of intersection ? I don't. N = [1 2 3 4 5 6]; P = [1.48982012272225e-09 1.20413388047633e-08 4.174352140114...

4 days ago | 0

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Error using SumOperator with Optimization Variables
nTasks = 3; nRess = 2; maxPT = 50; x = optimvar('x',nTasks,nRess,maxPT,'Type', 'integer','LowerBound',0,'UpperBound',1); Con...

4 days ago | 0

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Answered
plot based on if and else condition
MATLAB does not accept "double inequalities". Thus instead of if a < b < c you will have to use if a < b && b < c Further, ...

4 days ago | 0

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Is ode45 always calculate the entire function even if she has been asked only for specific values?
I mean, will it do the full calculation in the background and return only 3 points? Yes, it will do the full calculation in the...

4 days ago | 1

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Answered
Constrained dynamic optimization with fmincon
J is minimized in the objective function. The constraint T(x(t_final)) = 0 is set in the function "nonlcon" of fmincon. u (and...

5 days ago | 0

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Answered
Where/How exactly do I create an ODE Event Location Function?
if option == 1 % Choosing Straight Run Vs = 10 * (1852 / 3600); % [m/s]-S...

5 days ago | 1

Answered
How to solve a system of equations using the iteration by assuming the values of the unknowns and check them later. If the error is large return to change the assumed values.
Unknowns are epsilon_ri and zi. Equations are sigma_Ti = 0 and psi_i = psi_i_given. Two equations in two unknowns. Use MATLAB...

5 days ago | 0

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Answered
Using fmincon but converging to an infeasible point because the size of the current step is less than the value of the step size tolerance but constraints are not satisfied to
Works for me. T = 1000; %K R = 8.314; %kJ/kmol.K P = 300; %kpa in reformer Po = 100; %kpa standard conditions mair = ...

5 days ago | 0