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Torsten


2,135 total contributions since 2013

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Answered
How do I plot a 1-d random walk that generate 1 and -1 with equal probability? I am struggling to plot every individual P that I get against i the number of step.
n = 10; P = zeros(n,1); P(1) = 0; % Starting value for i=2:n % i is the number of steps from 1 to 10 R = rand; if R ...

20 hours ago | 0

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Answered
How to define multi variable linear programming ??
Set Z0 = x4, Z1= x5, Z2 = x6. Can you solve the problem now ?

24 hours ago | 0

Answered
Error using bvp4c: "Warning: Unable to meet the tolerance without using more than 5000 mesh points. The last mesh of 4921 points and the solution are available in the output argument."
If the code works for values of L0 smaller than 100, try approaching 100 by subsequently calling bvp4c with values L0start, L01,...

24 hours ago | 0

Answered
How can i generate random numbers according to a known probability?
https://en.wikipedia.org/wiki/Inverse_transform_sampling

2 days ago | 0

Answered
Why is the fval value so large when I use fzero to solve a equation which has Elliptical integral?
[betaxx,fval]=fzero(f1,[pi/2+0.01,3*pi/2-0.01])

3 days ago | 0

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Answered
How can I work out the rate of change for my experimental data?
rate_of_change_of_altitude = diff(altitude)./diff(time)

3 days ago | 0

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Answered
Fit an Ordinary Differential Equation (ODE) using lsqcurvefit
Remove parameters x(1) and x(2) from your list and introduce one new variable x(12). From x(12), calculate x1=5*cos^2(x(12)) and...

3 days ago | 1

Answered
Solving ODEs with different sets of initial conditions
function main n_times = 1000; t_i = 1; t_f = 10; tspan = [t_i,t_f]; y0 = randn(2, n_times); y0 = reshape(y0, 2*n_tim...

3 days ago | 0

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Answered
How do I output the second derivative from an ODE solver for further use?
After the line [t, r] = ode45('bubble', time_range, initial_conditions); insert for i=1:numel(t) t_actual = t(i); r_act...

3 days ago | 0

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Answered
How to solve first-order Taylor series expansion of two variable in MATLAB ?
https://de.mathworks.com/matlabcentral/answers/92764-how-do-i-generate-the-taylor-series-as-a-function-of-several-variables-in-m...

3 days ago | 0

Answered
How to evaluate a point in a solved differential equation in matlab?
y16 = interp1(xx,yy,1.6)

4 days ago | 1

Answered
singular jacobian encountered with bvp4c : constant-dependant result
function dydx = diffeq(x,y) % the function vector is as follows : y = [g; dg/dx; f; df/dx; h; dh/dx] dydx=ones(length(y),1); ...

4 days ago | 0

Answered
Finding the multiple zeros within a prescribed interval
deltax = 1e-4; xright = 100; n = floor(xright/pi); fun = @(x)tan(x)-x; for i=1:n left = (2*i-1)*pi/2.0 + deltax; right...

4 days ago | 1

Answered
Solution of mincon doesn't satisfy the nonlcon constraints
function main x0 = [1,1] A = [0 1] b = [40] lb = [0 0] ub = [10000 10000] [x,fval] = fmincon(@objfun,x0,A,b,[]...

4 days ago | 0

Answered
Stuck on rewriting program to use nested if constructs
if x>=0 if y>=0 ...; else ...; end else if y>=0 ...; else .....

5 days ago | 0

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How to implement tightly coupled nonlinear odes using ode45 in matlab?
Solve the equations t*x2 - x1*x2' = t^2*x1 + x2*x1' x1'' + x2'' = t*x2 - x1*x2' Setting y1 = x1 y2 = x1' ...

5 days ago | 0

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Answered
Calculate the integral in time of a variable that's being integrated with ODE15s
Add the equation d(tau)/dt = R^4 with tau(0) = 0 Then tau is available during integration. Best wishes To...

5 days ago | 0

Answered
Warning: Cannot find explicit solution
format long deltax = 1e-13; n = 100; ke = 3.7e-5; R = 2e-4; Dm = 12.6e-19; fun = @(x)x.*cot(x)-1+ke*R/Dm; ...

5 days ago | 0

Answered
ode45 say that return column vector using lsqcurvefit
function FF = BF(velocity1, a, dk1) n = 1; t_int = (0:0.0006:5.3994)'; velocity1_int = velocity1'; [xa] = ode4...

5 days ago | 0

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Answered
I am having trouble writing a ODE45 function for this bungee jumping problem.
Take a look at the ballode example: https://www.mathworks.com/examples/matlab/mw/matlab-ex84325677-simple-event-location-a-bo...

5 days ago | 0

Answered
ode23: using different sets of ODE equations at certain time intervals t
Take a look at the answer given here: https://de.mathworks.com/matlabcentral/answers/429332-using-ode45-to-solve-quarter-mode...

5 days ago | 0

Answered
Using ODE45 to solve quarter model of suspension with input function (an endless obstacle)
t = 0:0.01:0.25; phase = 1; y0 = [0 0 0 0]; [t1, y1] = ode45(@(t,y) fce(t,y,phase),t,y0); t = 0.25:0.01:3; ph...

5 days ago | 0

Answered
Parameter fitting problem: I use lsqnonlin to fit 3 parameters into a system of ODES and everything works fine until I inserted a Confidence Interval as one of my coefficients.At that point the fitted parameter vector took only the initial guess
Each time your ODE function is called, "rand" takes a different value between 0 and 1. This makes it impossible for the ODE solv...

8 days ago | 0

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Answered
Minimize non linear function with undefined vector
The examples given here should show you how to proceed: https://de.mathworks.com/help/matlab/ref/fminsearch.html

8 days ago | 0

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Answered
How we can solve the symbolic integral of the given function
Your integral equals b^(a+1)*(c/b*gamma(a)*gammainc(c/b,a)-gamma(a+1)*gammainc(c/b,a+1)) Best wishes Torsten.

8 days ago | 0

Answered
Solving linear convection equation (wave equation) by Lax Wendroff Scheme
N=100; %No. of grid points Tmax=1; % time period=1 alpha=1; %given h=0.01; %given value of delX delt=0.005; ...

8 days ago | 1

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Answered
How to fit a custom probability distribution to my data?
Since the integral from 0 to Inf must be equal to 1, it follows that a = b = lambda. This is the usual exponential distribution ...

8 days ago | 1

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Answered
How to stop the ODE45 at a defined condition during its execution ?
If you want a controlled shutdown, use the event function capability of the ODE solvers.

8 days ago | 2

Answered
How to insert square terms in constraints for fmincon
You must use function "nonlcon" for this.

9 days ago | 0

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