Answered
Computing Partial derivates of anonymous functions comprised of sum of standard functions
Stay numerical in your computation and approximate the gradient of your objective function "obj" by finite-difference quotients:...

1 year ago | 0

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Answered
How do I optimize/find the minimum of a multi-variable function?
If you don't restrict your x- and y- variables to certain lower and upper bounds, the minimum of the function your get from "fit...

1 year ago | 0

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Can I use fmincon with a whole model as function?
I don't see your problem. You call "fmincon" as sol = fmincon(@fun,x0) and write a function "fun" as function obj = fun(x) ...

1 year ago | 0

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Answered
Regarding choosing correct boundary condition
If you set qL = 1 and qr = 1 and you defined f as f = D*du/dx in the function where you need to specify [c,f,s], you can specify...

1 year ago | 0

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Answered
How to interpolate 2-parameter dependents matrices?
Use griddedInterpolant or scatteredInterpolant on each matrix element separately depending on whether the point pairs (Vi,qj) fo...

1 year ago | 1

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Answered
Mathematical Equations to MATLAB
%Parameters beta = 2; alpha = 200; Ccl = 2000; Cpm = 2500; Rl = 1100; Cren = 50000; delta = 0.223; P = 12; N = 8; Clo...

1 year ago | 0

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Answered
How can I replace NaN in a table with a zero?
https://uk.mathworks.com/matlabcentral/answers/231096-replace-nan-s-in-table-with-zero

1 year ago | 0

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ODE15i DAE Warning:Failure at t=0.000000e+00. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (0.000000e+00) at time t.
It can be deduced from your equations that the only possible solution for your DAE system is y(i) = 0 for i=1,...,8. Thus you c...

1 year ago | 0

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Answered
Solver Stop Prematurely as new equation added
Use an options structure for "fsolve" as options = optimset('MaxFunEvals',100000,'MaxIter',100000) sol = fsolve(...,options) ...

1 year ago | 1

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Please tell me what corrections can I make when encountering the following error?
We don't know the contents and sizes of the arrays you use. So we are unable to help. This would work e.g. : xspan = linspace(...

1 year ago | 0

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Can I solve more than two PDEs in 2D?
If you have a licence for the PDE Toolbox, you can apply it to solve your problem.

1 year ago | 0

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Answered
Iteration method of optimization
That's what I get from your description. But I might have misunderstood something. % Parameters m_values = linspace(0, 1, 100)...

1 year ago | 0

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Answered
Error using surf (line 71) Z must be a matrix, not a scalar or vector.
Before your loop insert the commands size(squeeze(ws(:,:,1))') size(we_m) size(sn_m) For surf to work, all sizes must be the...

1 year ago | 0

Answered
Unknown variables appearing in solutions for symbolic equation solver
syms x f = x^5+x^4+3*x^2-4; solve(f==0) vpa(solve(f==0)) double(solve(f==0)) I have no explanation for the u that appears i...

1 year ago | 0

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Answered
¿Por que me aparece el error de Incorrect number or types of inputs or outputs for function applyBoundaryCondition en mi codigo?
Instead of "edges", you have to include the edge number to which you want to apply the boundary condition. I plotted the geomet...

1 year ago | 0

Answered
Fitting multiple curves with multiple data sets, partial and globally shared parameters using lsqcurvefit
rng("default") b1 = 1; b2 = 0.85; b3 = 2.5; b4 = 1.1; b5 = 2.2; b6 = 4.5; b7 = 1.3; b8 = 7.2; b9 = 9.5; b10 = 0.5; %x data ...

1 year ago | 0

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Answered
Why is this matlab program not able to solve accurately?
Some equations cannot be solved analytically because they are too complicated or because there are no functions available that c...

1 year ago | 1

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Answered
I want to perform this time derivative?
From your description, you have 412 different dV_c/dt curves over time, one curve for each distance X. And now ? Do you want to...

1 year ago | 0

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Answered
NLP problem with fmincon: Non-differentiable point in objective function
The solution variables for "fmincon" must be continuous in order to compute gradients, Hessians etc. Therefore, the solver is no...

1 year ago | 0

Answered
solving nonlinear wave equation
Using the method of characteristics, you get the equations dt/ds = 1 dx/ds = v_max*(1-2*rho/rho_max) drho/ds = 0 You should ...

1 year ago | 2

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Answered
Is it possible to create a distribution fit (preferably gaussian mixture distribution model) for a distribution with precalculated bincounts?
The bincounts define a probability distribution. Draw random numbers from this distribution - they can be used as data in "fitdi...

1 year ago | 0

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How can i solve this eqaution in matlab?
I still don't understand where you can change t=0.1 s, t=20 s, t=60 s, but here we go: Rho_f = 920; %kg/m^3 Dp = 0.152; % m m...

1 year ago | 0

Answered
How can i solve this eqaution in matlab?
Rho_f = 920; %kg/m^3 Dp = 0.152; % m m_dot_oxi = 7.95; %kg/s n = 0.75; m = -0.15; a = 2.006e-5; Rp = Dp/2; % m A = pi*(Rp...

1 year ago | 0

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Answered
Finding accurate inverse of binary circulant matrix
BCM=readmatrix('MixingLayer.xlsx'); inv(gf(BCM,2))

1 year ago | 0

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Answered
finding value in 2d array function of x and y
Given (vehicle.wheeltorque ,vehicle.wheelspeed), use pdist2 to compute the distances to the column vectors of the matrix [Torque...

1 year ago | 0

Answered
How do I sort these 2D-Points to get a proper surf plot of this function
x = linspace(-1,1,1000); y = linspace(-1,1,1000); [X,Y] = meshgrid(x,y); Z = nan(size(X)); idx = X.^2+Y.^2 <= 1; Z(idx) = 1...

1 year ago | 1

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Answered
how to read mat file in matlab
https://uk.mathworks.com/help/matlab/ref/load.html

1 year ago | 0

Answered
Proving one function is greater than other?
syms x y f = 53.989/21.233 * (log(log(x))).^(4/3)./(log(x)).^(1/3); %x is solution where f starts getting greater than 1 xsta...

1 year ago | 0

Answered
Multicomponent gas separation in hollow fiber membranes
par.thickness_membrane = 1e-6; % thickness membrane [m] par.Perm_H2 = 250*3.35e-16; % Permeability H2 [mol m/m2 s Pa] par.Per...

1 year ago | 0

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Answered
How should I set the value of u_tau?
The problem simply is that you cannot solve delay PDEs with "pdepe", at least not directly. A possible remedy: Call "pdepe" in...

1 year ago | 0