Answered
How to draw the function relationship graph between two or three variables, where these variables are solved by a system of equations.
Here are the three possible solutions for VL given tc. % 定义符号变量 VL=20; syms tc t2 Q_out Vco Vcn VL %参数关系 L=100e-9; C=50e-6...

2 years ago | 0

Answered
Plotting a variable versus space and time
Use "slice": https://uk.mathworks.com/help/matlab/ref/slice.html

2 years ago | 0

| accepted

Answered
checkGradients, but the objective function has two inputs: x and xdata?
valid = checkGradients(@(p)semiCircle(p, Q),p0)

2 years ago | 0

| accepted

Answered
How can I evaluate the transition matrix using the fourth order Runge-Kutta ODEs
Seems to work. What's your problem ? Don't use the transition matrix to integrate in one pass. If you have to, generate it with...

2 years ago | 0

Answered
problem with vpa and symsum
The numerical bessel functions are not able to compute your sum correctly (for higher values of k, they return NaN) (see below)....

2 years ago | 0

| accepted

Answered
getting singular jacobian error while using bvp4c solver
I can't interprete your solution curves, but it seems to be a problem for the solver that the Scaled Mass goes to 0 with increas...

2 years ago | 0

Answered
Empty sym: 0-by-1 : Don't understand why
I multiplied by the denominators and squared to get rid of the square roots. Your system seems to have 4 (complex-valued) solut...

2 years ago | 0

| accepted

Answered
Non-linear least squares estimation with linear constraints in Simulink?
I vaguely remember that using "lsqcurvefit" within Simulink requires to use the Levenberg-Marquardt algorithm. I can't answer wh...

2 years ago | 1

| accepted

Answered
Do I have a convergence issue?
B0 = 0.5; B = fsolve(@fun,B0) function residual = fun(B) g = 10; %m/s^2 Q = 70*1000; %N/m tau_L1 = 24*1000; %Pa t_w = 30...

2 years ago | 0

Answered
HOw to find displacement integrating velocity?
The equation from above describes the stationary velocity profile over the length L. Thus replacing v by dx/dt does not make sen...

2 years ago | 1

| accepted

Answered
Integration symbiolic form in matlab gives error
I think you will have big problems if you try to integrate a function with values in the order of +/- 1e70. syms r theta Part_...

2 years ago | 0

Answered
Why the symbolic method fail when I tried to expand a ellipse
I get the correct result (at least for coe = [1;1;1;1;1;1]) : aex = expandA(ones(6,1)).' function aex = expandA(coe) A = co...

2 years ago | 0

Answered
Why did i receive error with my for loop ode45 function?
I used numerical values for L1, L2, mblade, kt and Jblade right from the beginning and got expressions for dL_dtheta2_numeric an...

2 years ago | 0

Answered
Why do i get the error (Array indices must be positive integers or logical values) when trying to calculate the determinant
I don't get any error. But you shouldn't overwrite the function "det" by using the variable name "det" for the result. Name it ...

2 years ago | 0

Answered
having if/else statement go to previous input
r = rand(); if opt == 1 || (opt == 3 && r < 0.5) abc else xyz end

2 years ago | 0

Answered
6x6 system of multivariate quadratic equations ... non-negative real solutions
I think there is no specialized solver for a system of quadratic equations. Thus a general nonlinear solver ("fsolve","lsqnonlin...

2 years ago | 0

Answered
Color Burr distribution function line
pd = makedist('Burr','alpha',1,'c',2,'k',5); R = random(pd,100,1); pd = fitdist(R,'Burr'); figure(1) plot(pd) x = 0:0.01:2;...

2 years ago | 0

| accepted

Answered
Writing ODE equations for ode45 to solve;
The form of the equations that can be solved by ode45 is M*y'(t) = f(t,y). So you can decide whether you choose M to be the iden...

2 years ago | 0

| accepted

Answered
How to use a solver to get the terminal velocity of a sphere.
v0 = fsolve(@fun,1) function res = fun(v0) d_p =...; rho_air = ...; nu_air = ...; rho_w = ...; g = ...; Re ...

2 years ago | 1

| accepted

Answered
Nusselt number and skin friction for bvp4c
Nu1 = -(1+bk*(1+m))*S1.y(5,1) Nu2 = -(1+bk)*S1.y(5,end) Tau1 = (1-bv*(1+m))*S1.y(4,1) Tau2 = (1-bv)*S1.y(4,end)

2 years ago | 0

| accepted

Answered
K Nested For Loops for arbitrary K
I'd generate all possible k-tuples out of the n numbers and throw away those that are not monotonic by using the "diff" command:...

2 years ago | 0

Answered
How to find non-zero solutions to underdetermined systems of equations
The null() function gives you a basis for ker(A): A=[0.719600000000000,0.069400000000000,0.526400000000000,0.110700000000000;1....

2 years ago | 0

| accepted

Answered
How to get the exact step size used by ode45?
If the stepsize is part of the ODE equation, you cannot use ODE45 to solve. You have to write your own integrator.

2 years ago | 0

| accepted

Answered
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,...

2 years ago | 0

Answered
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*...

2 years ago | 1

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

2 years ago | 1

Answered
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

2 years ago | 1

| accepted

Answered
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...

2 years ago | 0

| accepted

Answered
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...

2 years ago | 0

Answered
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...

2 years ago | 0