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How to solve a system of nonlinear differential equation that follows some pattern
function dy = fun(t,y) dy = y.*[y(2:end);y(1)] end or a function handle fun = @(t,y) y.*[y(2:end);y(1)]

2 years ago | 1

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Interpolating the y values of a dataset A to correspond to the x values of dataset B.
The easiest way I can think of is y1_at_x2 = interp1(x1,y1,x2) If it's precise ? Define precise. At least you have the choice ...

2 years ago | 1

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Hi, i try to solve equation c in terms of other variables, and its appear the messages and the answers is not as expected. Is supposed to be beta/p^(1/sigma)? is it?
Maybe you want to restrict the parameters to be positive (and thus real-valued): syms beta c sigma p positive eqn1 = beta/c^si...

2 years ago | 0

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How to solve 3 linear equations symbollically?
The first two equations in "velocity_eq" only have "omega_output_z" as variable and contradict each other (see above).

2 years ago | 1

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Problem with matrix dimensions
In "sistema", I made F a column vector by adding a last line as F = F(:); and it works.

2 years ago | 0

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Nonorthogonal eigenvectors for general eigenvalue problem with eig() and eigs()
From the documentation: [V,D] = eig(A,B) returns diagonal matrix D of generalized eigenvalues and full matrix V whose columns a...

2 years ago | 0

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Finding the minimum distance between two matrices
https://uk.mathworks.com/matlabcentral/fileexchange/34869-distance2curve Use one matrix to generate the curve and the other dat...

2 years ago | 0

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How to solve a fourth order differential equation (boundary value problem) with constraint?
And as far as I see, a necessary and sufficient condition that w'''' is bounded on [0 l] is w(0) = 0, and that's what you alread...

2 years ago | 0

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How to delete variables in a table within a cell array
for i=1:10 c{i}(:,1:2) = []; end

2 years ago | 0

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Index in position 1 exceeds array bounds. Index must not exceed 1.
A is a single value, namely A = b*h + z*h^2; % Cross-sectional area (m^2) But in your double loop, you treat A as if it we...

2 years ago | 0

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Why are these interations not working?
x1 = 16/2; y1 = 25/5; fyx = -1/2; fxy = 1/5; x2 = fyx*y1 y2 = fxy*x1; x3 = fyx*y2 y3 = fxy*x2; x4 = fyx*y3 y4 = fxy...

2 years ago | 0

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Crank-Nicholson method
I suggest the following code: xstart = 0; xend = 1; tstart = 0; tend = 1; nx = 10; nt = 100; x = linspace(xstart,xend,nx)...

2 years ago | 0

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Answered
Calculate total heat loss by conduction given temperature and depth profile vectors
Here is another way to determine the temporal change of heat content in the substratum. rho*cp*dT/dt = d/dx (k*dT/dx) Integrat...

2 years ago | 0

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Calculate total heat loss by conduction given temperature and depth profile vectors
How can I estimate the total heat loss (w/m2) at each time interval (i.e., the heat loss for every profile)? Total heat flow in...

2 years ago | 0

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data not generating and error in plotting
And what is the "correct" result ? According to your mathematical description, I get this: % Define initial parameters lambda...

2 years ago | 0

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Problem with the fitting
% Define the data dr_data = [2.5453, 0.042123; 5.0907, 0.075326; 7.636, 0.059506; 10.1813, 0.071553; 12.7267, 0.071365; 15.272,...

2 years ago | 0

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Second order coupled differential equation
X0 = [0; 0; 0]; % initial conditions r = linspace(1, 50, 100); % resistance range tspan = linspace(0,100, 100); freq_vector...

2 years ago | 0

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Use of Fmincon for stress relax data
I suggest you read the examples for the different suitable solvers. They will show you exactly how to proceed for your case. Ma...

2 years ago | 0

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How to use Matlab to generate a discrete uniformly distributed decimal with a value range of {0, 0.05} and a step size of 0.01?
n = 10; x = randi(6,n,1); x = (x-1)*0.01

2 years ago | 0

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use of pdepe for a space-dependent diffusivity
First: Don't name the vector "diff" since "diff" is an internal MATLAB function. Name it D, e.g. Second: To get the correct val...

2 years ago | 0

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If I have an array and I need to find an element in the array how do I go about it?
Compute 100*states(:,1)+10*states(:,2)+states(:,3) and use "find" to compare with C.

2 years ago | 1

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Solve a differential equation and determine when it gets close to steady state
You can use an event function for the ODE integrator and stop integration when abs(dy/dt) (in your case abs(0.1 * (c-20) * (23-c...

2 years ago | 0

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the degradation of ozone in aqueous solutions (water). When I plot the all three components, the plot stays at the 0 value for all components.
There seems to be a singularity in the solution at t approximately 320. ProjectOzone() function ProjectOzone clc ki = 7e-3;...

2 years ago | 0

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The code below runs nonstop, and the results are not shown. why is that?
The code below runs nonstop, and the results are not shown. why is that? "solve" won't succeed for your system of equations bec...

2 years ago | 0

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Create number of for loops depending on size of N
The N columns of the resulting C-matrix contain i_first, i_second,... imax = 8; N = 4; i_average = (sum(0:N-1)/N+sum(imax:-1:...

2 years ago | 0

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How to make Matlab recognize that an expression rewritten by using subexpr() is equal to the original expression?
You have to resubstitute sigma by (a+b+c+d+e)^(1/2) in x_2 to compare with x: syms a b c d e f x x = a + (a+b+c+d+e)^(1/2) + c...

2 years ago | 0

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plot the output c(t) using mathlab and show setting time on you graphf
Use "fplot" as done in your code above.

2 years ago | 0

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Describe the solution trajectory of differential systems with mixed time-varying delay
To write your equations as a system of delay differential equations that can be handled by a MATLAB solver, set x3 = integral_{...

2 years ago | 1

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Plot between Nu vs Ra
Replace Ra_values = 10:100:100000; by Ra_values = (10:100:100000).';

2 years ago | 0

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Resetting only a section of my state during event driven ode45 simulation
After the event has been triggered, control is returned to the calling program. If you want to continue integration with the e...

2 years ago | 1