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...

1 month ago | 1

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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...

1 month ago | 0

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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...

1 month ago | 1

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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_...

1 month ago | 0

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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 months ago | 0

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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 months ago | 0

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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 months ago | 0

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

2 months ago | 0

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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 months ago | 0

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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 months ago | 0

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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 months ago | 0

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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 months ago | 1

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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 months ago | 0

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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 months ago | 0

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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 months ago | 0

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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 months ago | 0

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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 months 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 months ago | 1

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

2 months ago | 1

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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 months ago | 1

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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 months ago | 0

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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 months ago | 0

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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 months ago | 0

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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'.

2 months ago | 0

Answered
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...

2 months ago | 0

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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...

2 months ago | 0

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Answered
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 months ago | 0

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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(...

3 months ago | 0

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Answered
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...

3 months ago | 0

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

3 months ago | 0

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