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What happens if I set both RelTol and AbsTol for ODE45 and/or both TolX and Tolfun for FSOLVE?
Do these functions refine steps, etc. until both requirements are satisfied or only one of them? Both. Read about error contro...

2 meses hace | 0

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Which statistic is minimized in curve fitting app
My question is what parameter/statistic is minimized to make a fit? SSE (maybe weighted if you specify weights for the measurem...

2 meses hace | 1

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Help with MATLAB symbolic toolbox
Can't you use "dsolve" ? If not, use % Find the value of C1 interm of C2 C1_sol = vpa(solve(yp, C1),4) % Sub C1 into equat...

2 meses hace | 0

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Find limits satisfying a condition on an integral
x = linspace(0, 2*pi, 20); y = sin(x); lowLimIndex = 1; target = 2; [~,upLimIndex] = min(abs(cumtrapz(x(lowLimIndex:end),y(l...

2 meses hace | 0

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How plot density of function ?
Your function only depends on x, not on x and y. I'm not sure how you want to make it 2d. Thus I simply defined g(x,y) = f(x)*...

2 meses hace | 1

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Problem with lsqnonlin and error function implementing a bovine pericardium constitutive model
strain(1) = 0 - thus you must remove the first data point since you divide by strain(i). Maybe your model function does not all...

2 meses hace | 1

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Error on Symbolic calculation : "Empty sym : 0-by-1"
v1 = [393 393 393 393 393 393 393 393 393 393 ; 3850 4340 4760 5320 5740 6160 6580 7140 7980 8960]; v2 = [408 408 408 408 408 4...

2 meses hace | 0

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Erron on Symbolic calculation [Case 2] : "Empty sym : 0-by-1"
If Λ is some kind of maximum likelihood function you try to maximize, I suggest you use "mle". We had this problem already - I ...

2 meses hace | 0

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cosine of a matrix returns weird values.
"cos" and "tan" can be applied to angles in radians, not in degrees. Use "cosd" and "tand" instead.

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How can I use Createpde to solve a fourth degree partial differential equation?
You have a system of two second-order differential equations. Thus instead of defining one equation, you have to define two and ...

2 meses hace | 1

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mono- objective optimization and multiopjective optimisation, I would like to use GA with option but there is a fault that I can't to resolve
You mean objective = @(x) 1.002 - ((1 - exp(-0.00003 * x)) ./ (0.00003 * (x + 1.5) + 0.00063 * (1 - exp(-0.00003 * x)))); a = ...

2 meses hace | 0

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How to place random CNT's in a box domain with random curves and orientation ?
https://uk.mathworks.com/matlabcentral/fileexchange/93250-generate-thick-fibers?s_tid=srchtitle

2 meses hace | 0

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how to use fmincon to optimize a functio with more than one control vector where the control vectors used in constrains also?
If all three vectors/matrices are to be treated as solution variables for "fmincon", use v = [p(:);X(:);L(:)] It's useful to t...

3 meses hace | 1

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Double Integration of Numeric Data - Acceleration -> Displacement
Assuming x(0) = v(0) = 0 in both cases, I get load("A2.mat") load("A9.mat") a2 = Datashort1; a9 = Datashort21; figure plot...

3 meses hace | 0

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Find real valued parameters of a complex equation/model by using optimization or curve fitting.
I don't know if this helps to get better results, but of course you have to fit real and imaginary part of mu_eff simultaneously...

3 meses hace | 0

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Storing while loop results in an array and plotting
Why do you think the results you get from the second part of your code are wrong ? g = 10; y(1) = 100; v(1) = 0; t(1) = 0; ...

3 meses hace | 0

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how to solve this error? Objective function is returning undefined values at initial point. FSOLVE cannot continue.
In the computation of c0,...,c10, you divide by x(3),...,x(13), thus by 0 because x0 = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] . After ...

3 meses hace | 0

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4th order Runge - Kutta vs. 4th order Predictor - Corrector
%--- Exercise 1 - A %--- Solving the diff. eqn. N'(t) = N(t) - c*N^2(t) with c = 0.5 using %--- Euler's method, Runge - Kutta ...

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4th order Runge - Kutta vs. 4th order Predictor - Corrector
For k>4, the variable RKN should no longer appear in the equations PredN(k) = PredN(k-1) + h/24*( 55*f(t(k-1),RKN(k-1)...

3 meses hace | 0

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Runge - kutta 4th order method for two different steps
y(j+1) = y(j) + h(i)*(K1 + K4 + 2*(K2 + K3))/6; instead of y(j+1) = y(j) + (K1 + K4 + 2*(K2 + K3))/6;

3 meses hace | 0

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Error using surf (line 71) Z must be a matrix, not a scalar or vector.
Works for me (assuming that FL_hat is 1001x1001 in your case): alpha = linspace(0, 2*pi, 51); beta = linspace(0, 2*pi,21); FL...

3 meses hace | 0

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How to avoid the warnings on my code
%--- Solving the diff. eqn. y'(t) = y(t) - c*y^2(t) with c = 0.5 using %--- Euler's method, Runge - Kutta method, and predictor...

3 meses hace | 1

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I am new to using Matlab, and wanted to ask if there is a way to group datapoints into bins/columns by numerical range? Thanks
https://uk.mathworks.com/help/matlab/ref/double.discretize.html https://uk.mathworks.com/help/matlab/ref/matlab.graphics.chart....

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Plugging a new value to ksdensity
rng("default") r = randn(100,1); x_new = 1.1; f = ksdensity(r,x_new) or rng("default") r = randn(100,1); f = @(x)ksdensit...

3 meses hace | 0

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which software better to learn?
If you ask this in a MATLAB forum, you will get a different answer than in a python forum :-) If you start learning about optim...

3 meses hace | 1

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Hello everyone, I have a question about numerical integration. The formula is shown below, where the integration path C_beta is a closed curve on the complex plane.
However, as mentioned in my question, the array list_beta forms a closed curve on the complex plane. Isn't then dq = q' dbeta a...

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graph is not showing
P=1; % assuming and constant Ex=20*10^4; Ey=2*10^4; Ea=0.1*10^4; k=0.1; t=0.01; b=0.05; h=0.1; ExGxy=17; Ah=((Ex/Ey)^0....

3 meses hace | 0

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Diffusion equation in Cartesian and Cylindrical coordinates
If m = 1, the condition at r = 0 set by "pdepe" is pl = 0, ql = 1. All other conditions make no sense mathematically because the...

3 meses hace | 0

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"Too Many Input/Output Arguments" error for nrlmsise00 function
The results for the defined testcase seem to coincide with what is stated in the Documentation (see below). You will have to ad...

3 meses hace | 1

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Weighted regression without priority zone, but with finding the minimum possible value for all the differences
x = [1 2 3 4 5 10 20 50].'; y = [5 10 15 20 25 30 40 50 60 90]; z = [265.110074796797 195.008035083193 156.258229529605 129.74...

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