photo

Torsten


Last seen: Today Con actividad desde 2013

Followers: 17   Following: 0

Estadística

  • Most Accepted 2023
  • Most Accepted 2022
  • Explorer
  • Master
  • 36 Month Streak
  • Revival Level 2
  • Knowledgeable Level 5
  • First Answer

Ver insignias

Feeds

Ver por

Respondida
System of state dependent delay equations causes ddesd to run forever.
y(5) is negative shortly after t = 0. Thus your delay d = t - y(5) in principle would refer to values of y(1) that are not yet k...

alrededor de 6 horas hace | 0

Respondida
Integrating multivariate Gaussian pdf in 4 dimensions
Use "mvncdf": https://uk.mathworks.com/help/stats/mvncdf.html If your function is more complicated than posted, try "integralN...

alrededor de 21 horas hace | 0

| aceptada

Respondida
The mean function isn't working and i don't know why
Check whether the data type of Data_IV_KE is "double". To this end, MATLAB should return "double" when you type class(Data_IV...

3 días hace | 0

Respondida
Solving Second-Order BVP with unknown Constants using fsolve
solinit = bvpinit(linspace(-6.17415,6.17415,64),[0;0],[.809827,0]); sol = bvp4c(@mat4ode,@mat4bc, solinit); xint = linspace(...

4 días hace | 0

| aceptada

Respondida
Hi,I tray RUN this code but i get tis error ( below the code)
Variables and/or functions are missing to run your code. According to the error message, m90_plot is an array of size 12784, bu...

4 días hace | 0

Respondida
expressing the complex function
Use syms x t real instead of syms x t Then real(series) and imag(series) will work.

6 días hace | 0

| aceptada

Respondida
beginner integration trouble.
"int" cannot find an analytical antiderivative for f(x). Thus to get the numerical value for the integral, use Area=2*vpainte...

6 días hace | 0

| aceptada

Respondida
Using erfcinv and array indices are being rejected as not positive or valid, despite all being positive in the vector
As far as I understand, "erfbatp" is an array of numbers. So erfbatp(2*.05/2) = erfbatp(0.05) does not make sense, does it ? V...

7 días hace | 0

Respondida
Converting symbolic ODE solution to function ... Warnings
The solution is implicitly given by the equation (a*y+b*y^2/2+c*y^3/3+d*y^4/4)-(a*y0+b*y0^2/2+c*y0^3/3+d*y0^4/4) - integral_{x'...

8 días hace | 0

Respondida
convert the above expression into this graph
I'll show you how to solve for theta2 given theta from the equation sin(theta2-theta)+exp(-theta2/(omega*tau))*sin(theta)=0 F...

8 días hace | 1

| aceptada

Respondida
Trouble using ODE45 for coupled non-linear differential equation
I can't recover the four differential equations you solve from the two equations you included in mathematical form. Your equati...

8 días hace | 0

Respondida
How to get the answer from the following code. How can i extract the values from the code?
F = U1.y(5,1)-Nt*U1.yp(5,1) J = -1i*U1.y(6,1) N1 = -U1.y(7,1) N2 = -U1.y(8,1)

9 días hace | 0

| aceptada

Respondida
Explicit method for Allen-Cahn equation
xstart = -1.0; xend = 1.0; nx = 401; x = linspace(xstart,xend,nx).'; dx = x(2)-x(1); tstart = 0.0; tend = 1.0; nt = 10; ...

9 días hace | 0

| aceptada

Respondida
How to fill a variable with the results of an if...elseif statement
Use imin = 0; imax = 0; isaddlePts = 0; iinconcl = 0; for ind = 1:9 D=fxx(Xc(ind),Yc(ind))*fyy(Xc(ind),Yc(ind)) - (fx...

10 días hace | 0

| aceptada

Respondida
Need to rectify error in my matlab code given below
I want to get a plot of dn/dt versus t. syms t mu=2500*(10^-4); %cm^2*V^-1 * s^-1 R = 0.318; eta=377;% ohm N=3.681; %refind...

10 días hace | 0

Respondida
Using Runge Kutta to solve second-order differential equations with two degrees of freedom
I don't understand from your code if you want to perform a parameter study for 1000 different values of omega or if you want to ...

11 días hace | 0

Respondida
Cannot get fmincon to work
clear close clc format long %% Variables dp = 11.6; taup = 3710e-6; dn = 2; taun = 371e-6; Jl = 50e-3; ni = 9.696e9; ...

11 días hace | 1

| aceptada

Respondida
I continue to get this error and can't figure out how to fix it, Unable to perform assignment because the size of the left side is 1-by-4 and the size of the right side is 1-b
If you take the derivative of a polynomial, the degree of the resulting polynomial is one less than the degree of the original p...

12 días hace | 0

Respondida
coupled differntial equation using ode45
G = 1; Na = 1; xstart = -1; xend = 1; nx = 51; x = linspace(xstart,xend,nx); solinit = bvpinit(x, [0;0;1;0]); sol = bvp...

14 días hace | 1

| aceptada

Respondida
coupled differntial equation using ode45
syms y mu0 G Na U(y) T0(y) eqn1 = diff(mu0*diff(U,y)) == G; eqn2 = diff(T0,y,2) + Na*mu0*(diff(U,y))^2 == 0; conds1 = [U(-1)=...

14 días hace | 0

Respondida
Using tabular data for Curve fitting of function z = f (x, y) with incomplete values of z. These blank z (i, j) automatically takes zero values and this is a problem
green = [5 5 5 5 5 4 4 4 4 1 1 1]; blue = [5 10 15 20 25 5 10 15 20 5 10 15]; yellow = [455 322 261 205 169 410 306 246 191 25...

15 días hace | 1

| aceptada

Respondida
Numerical method of the "fimplicit" function
Since you can specify a mesh density in x- and y- direction, my guess is that the function is simply evaluated on X x Y. Sign ch...

15 días hace | 0

Respondida
My roots don't match example roots when solving routh criterion
syms K s p = s^3+9*s^2+12*s+15+3*K; solve(p,s,'MaxDegree',3) var2 = vpa(ans); var = subs(var2,K,-1)

16 días hace | 0

| aceptada

Respondida
Interrupt a while loop with functions if it takes too long
Is there a way of timing the iteration during its execution and break it? No. You could go into the function and time certain o...

17 días hace | 1

| aceptada

Respondida
How to solve the system of time dependent coupled PDE's?
ode23t seems to work for high Reynolds numbers. In case ode23t fails (e.g. for the low Reynolds number regime), I recommend the ...

18 días hace | 1

Respondida
Problem with my gamma_water values not giving me the correct pressure using fsolve
Look at the curves and see what's happening. Your first equation has two solutions while your second has none: DelH = -1* (-917...

20 días hace | 0

Respondida
An absolutely ascending sequence
x = 0:10; all(diff(x)>0)

20 días hace | 0

| aceptada

Respondida
Find zero of simple monotonic function where the independent variable can only be integer
If you know a lower integer value xl and an upper integer value xu with y(xl)*y(xu) < 0, you could do a binary search starting f...

20 días hace | 0

Respondida
Model simulation Code for SEIR
seir_simulation() function seir_simulation() % Parameters beta = 0.3; % Effective contact rate without control sigma = 1/5; ...

20 días hace | 0

Respondida
using loops and arrays to solve for variables in equations
You mean this ? x=zeros(5,1); vis=zeros(5,1); %strain rate epsUse=1e-14; Puse=1e9; PARAMS.R=8.314; %ideal gas constant %d...

20 días hace | 0

| aceptada

Cargar más