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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...

oltre un anno fa | 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 ...

oltre un anno fa | 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 ...

oltre un anno fa | 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 = ...

oltre un anno fa | 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

oltre un anno fa | 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...

oltre un anno fa | 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...

oltre un anno fa | 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...

quasi 2 anni fa | 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; ...

quasi 2 anni fa | 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 ...

quasi 2 anni fa | 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)...

quasi 2 anni fa | 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;

quasi 2 anni fa | 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...

quasi 2 anni fa | 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...

quasi 2 anni fa | 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....

quasi 2 anni fa | 0

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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...

quasi 2 anni fa | 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...

quasi 2 anni fa | 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...

quasi 2 anni fa | 0

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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....

quasi 2 anni fa | 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...

quasi 2 anni fa | 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...

quasi 2 anni fa | 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...

quasi 2 anni fa | 1

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Risposto
Code Matlab for a function that depends in a real parameter
integrand = @(f,y)y.*sin(f(y)); F_alpha = @(f,alpha,x)alpha.*x.*integral(@(y)integrand(f,y),0,1); f = @(u)u.^2; alpha = 1; x...

quasi 2 anni fa | 0

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Weighted regression without priority zone, but with finding the minimum possible value for all the differences
Use "fminimax". It minimizes the maximum error and is the nonlinear equivalent to minimizing the Inf-norm in linear regression p...

quasi 2 anni fa | 2

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Why am I getting error using assignin and syms while solving pde using pdepe
Here is the code for the dimensional model. It should be no problem to rewrite it in the non-dimensional form. Note that the s...

quasi 2 anni fa | 0

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Why am I getting error using assignin and syms while solving pde using pdepe
tau is a vector of values in your code: tau = linspace(0, tau_end, 100); % Non-dimensional time You can't use it as a symbolic...

quasi 2 anni fa | 0

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Andrica's Conjecture
Use nthprime(1:n+1) to generate the vector of the first n+1 prime numbers. The rest should be simple.

quasi 2 anni fa | 0

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Forward, Reverse finite difference question
x = 0:0.1:1; f = @(x)x.^2; derf = (f(x(2:end))-f(x(1:end-1)))/0.1; hold on plot(x(2:end),derf); % backward plot(x(1:end-...

quasi 2 anni fa | 1

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