Answered
Error in ode45 and 'Events' of a Satellite Tracking Radar Model
The "tspan" vector you provide for "ode45" has no influence on the internal time steps taken by the integrator. In zones with st...

11 months ago | 0

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I have been trying to derivate equation under to find the formula for 3 parameters Weibull distribution as same as picture. Can someone please help me fix it?
This code works, but it will not give you the result you want. syms m sigma_i sigma_0 sigma_th i N lnL = symsum(log((m/sigma_0...

11 months ago | 0

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How to vectorize analytical derivative functions for bvp4c?
Only the computation of the vector-valued derivatives function f can be vectorized, not the computation of its analytical deriva...

11 months ago | 0

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Answered
can't run applyBoundaryCondition
"applyBoundaryConditions" is used for general PDE models. You want to use the "thermal" model. The available properties and ob...

11 months ago | 0

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pdepe boundary condition help!!
Note that the f you define in "pdefun" doesn't fit the formula from the paper. You forgot to multiply both terms with m_d/lambda...

11 months ago | 0

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Answered
I must solve ode equation system but dsolve gives me error
The third boundary condition is wrong as stated. You must use dv/ds at some position s (e.g. 200). %Geometric and Inertial Par...

11 months ago | 0

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Answered
How can I change a variable and collect an vector of outputs?
V_array = 0.5:0.1:20; % Material Parameters c0 = 0.2; % Alloy composition k = 0.28; % Partition Coefficient (conc solute in s...

11 months ago | 1

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MLE of combined analytically and empirically defined distributions
MATLAB's "mle" accepts custom pdf's. If you write b as sin^2(p) and (1-b) as cos^2(p), it should work to estimate mu, sigma an...

11 months ago | 0

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Plot function for different values of two coupled variables
k5 = [0.1 0.2 0.3]; k6 = [0.3 0.5 0.7]; colors = ['b','r','g']; N = 3; hold on for i = 1:N [time,p,m] = fun(k5(i),k6(i...

11 months ago | 0

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I need to create a cicle in which, for a specific value, it solves one set of equation or another. It doesn't compute.
Works for me. Maybe you use an older MATLAB release ? Lcz = 10; %Contact lenght [mm] delta0 = 25; %Softening Lenght [mm] delt...

11 months ago | 0

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Answered
Variable might be set by a nonscalar operator
%% Define varaibles theta_deg=10:1:80; %% theta in 1 degrees increments theta_incline=18.05; theta_decline= 40.65; M=1; % ma...

11 months ago | 1

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Answered
Can I specify different thermal conductivities for different regions in a space using Matlap PDE Toolbox? For example, the space is divided into a thermal conductivity space o
There are two ways: A good method is to generate the geometry such that it consists of a certain number of zones to which you c...

11 months ago | 0

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Answered
Finding x and y values of minimum z in 2-variable function.
z = @(x,y)(x.^2).*(y.^3)-1.4*(x.^2).*(y.^2)-3.91*(x.^2).*y+5.78*(x.^2)-... 11*x.*(y.^3)+15.4*x.*(y.^2)+43.01*x.*y-63....

11 months ago | 0

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Find best fit curve from multiple curves of different size
I parametrized the curves by normalized arc length. To compute the average curve, I took the mean of R- and Z-coordinates of the...

11 months ago | 0

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How can I get splines subject to constraints?
This code looks helpful for your purpose: https://uk.mathworks.com/matlabcentral/fileexchange/7976-random-number-from-empirical...

11 months ago | 0

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Answered
How do I edit a loop to be able to store the variables and outputs used in each loop in a way which can be graphed?
Be careful here. In correlations for friction factors, log is usually meant as log to the basis of 10, not the natural logarithm...

11 months ago | 0

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Answered
Question solve(eqn)
Replace solve (f1, f2, f3, f4, f5, f6) by [a0,a1,a2,a3,a4,a5] = solve (f1, f2, f3, f4, f5, f6) But note that extrapolating t...

11 months ago | 0

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find is not working in a loop, it skips numbers
Never test two double precision numbers for equality. Because of floating point arithmetic, they will almost always be classifie...

11 months ago | 0

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Answered
Can someone rectify this code?
My guess is that you work with an older MATLAB version where script and function parts cannot be mixed. Thus save function F =...

11 months ago | 0

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elseif that goes through previous statements but with different parameters
if e(t)==1 nn1 = nn11; nn2 = nn21; elseif e(t)==2 nn1 = nn12; nn2 = nn22; elseif e(t)==3 nn1 = nn13; nn2 = nn23...

11 months ago | 0

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syms to another .m file
Call the other .m-file with the syms-equation (or function) as input argument. syms x f = x.^2; result = fun(f) function res...

11 months ago | 0

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Clarification regarding Sensitivity Analysis of a coupled ODE system using the odesensitivity function
Start with the simple example y'(t) = p(1)*y(t), y(0) = 1. The solution is y(t) = exp(p(1)*t). The (local) sensitivity is ...

11 months ago | 1

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Answered
How to make ode45 store/return only results of every n-th time step to reduce memory use?
You can specify the times when the solution should be saved in the input variable "tspan" to "ode45". And you should test wheth...

11 months ago | 1

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Answered
Energy Harvesting of Cantilever Beam with MSMA alloy1
I inserted "warning('off')" at the start of your code because your matrix M in your function "system_eqs" is singular and MATLAB...

11 months ago | 0

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Answered
Sampling from inverse gamma distribution by specifing mean and standard deviation
It works for mu = 0.5, sig = 0.5, e.g. . It seems that your distribution parameter "a" is too close to the critical value of a =...

12 months ago | 0

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Answered
How to code an equation with that integrates a vector.
If there is no closed-form expression for u (e.g. if u depends on x), you can solve the vector-differential equation dx/dt = u ...

12 months ago | 0

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The surface area won't round to one decimal place and I don't know how to get rid of the 'e's.
https://uk.mathworks.com/help/matlab/ref/fprintf.html https://uk.mathworks.com/help/matlab/ref/format.html

12 months ago | 1

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Need to correct the following script in part of Infinitely Long Horizontal Cylinder (to be of perfect circular base)
%% 2. Infinitely Long Horizontal Cylinder subplot(1,3,2); theta = linspace(0, 2*pi, 30); x_v = linspace(-10, 0, 20); [Theta,...

12 months ago | 0

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Answered
Grey box model of 1d heat diffusion in a rod (official mathworks example)
I think it will be simpler to couple "pdepe" for the solution of your PDE and "lsqnonlin" for optimizing your model parameters. ...

12 months ago | 0

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Answered
trouble using pdepe to solve system of pdes
Your initial condition for u(2) at x = 0 is not consistent with your boundary condition. Use function u0 = icfun(x) global ...

12 months ago | 0

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