Beantwortet
Optimization Eigenvalue problem Stiffness matrix
Should be % Perform optimization [K_opt_vec,~,res] = lsqnonlin(@(K) obj_function_reshaped_matrix(K, M, f_exact_Hz), [k1_guess,...

etwa ein Monat vor | 0

Beantwortet
MATLAb Solve function not solving
Which MATLAB version are you using ? R2024b gives a direct answer: clear all close all syms I1 I2 V0 s=2; eqns=[5*I1+4*...

etwa ein Monat vor | 1

Beantwortet
how can I calculate euler constant
g = vpa(eulergamma())

etwa ein Monat vor | 1

Beantwortet
How to find the equation of a 2D plane that best fits a set of vectors defined in n dimensions?
https://stackoverflow.com/questions/48200261/fit-plane-to-n-dimensional-points-in-matlab

etwa ein Monat vor | 1

| akzeptiert

Beantwortet
How to obtain direct symbolic solutions without introducing intermediate variables like z and z1 in MATLAB's solve function?
If it can't, I want to see what is the z and z1 in the solution. k,l,x,z and z1 are arbitrary numbers that satisfy joint_soluti...

etwa ein Monat vor | 0

| akzeptiert

Beantwortet
How to Set a Minimum Step Size for Variables in GA Solver (Global Optimization Toolbox)?
Define 21 integer variables x_i that can take values 0 or 1 (by using the "intcon" input to "ga" and setting the lower and upper...

etwa ein Monat vor | 0

Beantwortet
Trying to create a polynomial using data from a table
You can't expect exact agreement, but the approximation is not that bad (at least for the point chosen): % Data preparation dP...

etwa ein Monat vor | 0

Beantwortet
Algebraic variable derivatives in the DAE solution process
0 = dg/dx * x' + dg/dy * y' + dg/du * u' = dg/dx * f + dg/dy * y' + dg/du * u' Solve for y'.

etwa ein Monat vor | 0

Beantwortet
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...

etwa ein Monat vor | 0

Beantwortet
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...

etwa ein Monat vor | 0

| akzeptiert

Beantwortet
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...

etwa ein Monat vor | 0

Beantwortet
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(...

etwa ein Monat vor | 0

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

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

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
How to loop through values?
Beta = linspace(0,1,10); Alpha = linspace(0,2,20); n = numel(Beta); m = numel(Alpha); Result = zeros(n,m); for i = 1:n ...

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

Beantwortet
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'...

etwa 2 Monate vor | 0

Beantwortet
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...

etwa 2 Monate vor | 1

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

Beantwortet
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)

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
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; ...

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

Beantwortet
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 ...

etwa 2 Monate vor | 0

Beantwortet
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; ...

etwa 2 Monate vor | 1

| akzeptiert

Beantwortet
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...

etwa 2 Monate vor | 0

Beantwortet
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...

etwa 2 Monate vor | 1

| akzeptiert

Beantwortet
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)=...

etwa 2 Monate vor | 0

Beantwortet
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...

etwa 2 Monate vor | 1

| akzeptiert

Mehr laden