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Monitoring Variables Defined Within Functions to Debug
After the variable is computed, you can list the variable's name by itself on it's own line in your function code, with no semic...

3 months ago | 0

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ddesd giving NaN for all state variables beyond time step 1.
The history function has to cover values for t that are negative (because y6 becomes large and you have to supply y1(t-y6)). But...

3 months ago | 0

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Extracting coefficients from symbolic expression
syms P121 P131 P151 P122 P132 P152 cosdphi12over2 cosdphi13over2 cosdphi15over2 sindphi12over2 sindphi13over2 sindphi15over2 P12...

4 months ago | 1

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Iterative of Nonlinear Functions
Why do you use "solve" to get t1,...,t15 ? You can directly solve for the unknowns because you use the explicit Euler method to ...

4 months ago | 0

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Possible bug in coneprog.m function
This works for dense matrices/vectors, but in sparse mode, it gives exitflag = -7 as above. Maybe it's worth asking MATLAB suppo...

4 months ago | 1

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How can we plot the same time history plot two times but the second time with a time delay of 2 sec?
You mean t = 0:0.1:20; p = t.^2; hold on plot(t,p,'b') plot(t+2,p,'r') hold off grid on ?

4 months ago | 0

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Answered
plotting 2 figures in same for loop
figure hax1=axes; hold(hax1,'on') figure hax2=axes; hold(hax2,'on') x=1:5; for i=1:6 if rem(i,2)==0 scatter...

4 months ago | 0

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Answered
Solving differential equations with state variables and co-states
This code works, but gives no solution for the parameters given. %% Title: Solving Hamiltonian Objective Function using system ...

4 months ago | 1

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Answered
Finding if the current data value is greater than the previous value
It would help if you include the GDF-file. Without further information, I'd suggest T = readtable ("GDF.xlsx"); A = table2arr...

4 months ago | 2

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Answered
How to multiply different size arrays and multiply each element by each element?
If nothing helps, make a 4-fold nested loop. for i=1:numel(Span) for j = 1:numel(MAC) for k = 1:numel(CoM) ...

4 months ago | 0

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Combine non integer time steps into daily values
@Cristóbal Looking at the volume values, I'm almost sure that these values are already cumulative values. Why should the increa...

4 months ago | 2

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Programming wave dispersion equation
Code taken from https://uk.mathworks.com/matlabcentral/fileexchange/156009-wavelength-calculation-based-on-dispersion-relations...

4 months ago | 0

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Answered
Modelling a system of differential equations with recurrences in matlab
N = 20; k = 1; a = 1; b = 1; c = 1; d = 1; u0 = zeros(N,1); udot0 = 0.5*ones(N,1); v0 = zeros(N,1); vdot0 = 0...

4 months ago | 0

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Answered
How can received my license?
Either through the IT department of your university or - if you have an individual licence - by contacting MATLAB support: http...

4 months ago | 1

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Please help me to solve this simple error
@Walter Roberson answered the question about your MATLAB error. Concerning the problem you try to solve: I assume d1, d2 are ...

4 months ago | 0

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Curve fitting with a custom equation
Only round brackets are allowed in your expression. But maybe there are additional problems. If the code does not work after r...

4 months ago | 0

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Trying to figure out a algorithm to filter out some data, since I dont have any additional toolbox.
load("eeandv.mat") tol = 0.005; idx = abs(diff(e)) <= tol; e = e(idx); v = v(idx); plot(v,e) grid on; grid minor; xlim([...

4 months ago | 1

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I want to avoid fractions in my answer to the null space
Insert for i = 1:size(N_A,2) [~,d] = numden(N_A(:,i)); N_A(:,i) = N_A(:,i)*lcm(d); end after computing N_A.

5 months ago | 0

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Prevent "any Matlab service" from loading on Windows 11 startup.
Follow the instructions given here: https://uk.mathworks.com/matlabcentral/answers/101038-why-is-matlab-always-running-in-the-b...

5 months ago | 0

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why does set(gca) not working
The set command must be placed after the plot command, not before: FONT_SIZE = 16; max_iter = 10; x = 1:max_iter; % this is t...

5 months ago | 0

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Answered
Naming Table Variables of a File
load("T.mat") T1 = splitvars(T); T1 = renamevars(T1,["rows_1" "rows_2" "rows_3" "rows_4" "rows_5" "rows_6"],... ...

5 months ago | 1

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Answered
Error using countOnes = sum(num); when trying to count how many zeros and ones are randomly generated.
Works in R2025A (see above). I suspect that somewhere in your code, you define a variable with name "sum". Rename it because it...

5 months ago | 1

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Please i need to plot 3 dimension figure with (x axis is x, y axis is gamma function) and z axis is value of u for this simple attached relation
We don't know your problem, but it should work somehow like this. What do you mean by "the y-axis is the gamma function" ? Do ...

5 months ago | 0

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Plot: index exceeds array bounds ("Index in position 1 exceeds array bounds. Index must not exceed 1.")
Rename the struct "plot" which appears in your workspace. It's probably in conflict with MATLAB's "plot" function.

5 months ago | 1

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Answered
Plotting sum of two vectors
%Parameters or =0.2; oc = 0.2; gamma = 0.01; gam=0.01; Gamma = 1; Gamma1 = Gamma; Gamma2 = Gamma; Gamma3 = 9/10; Gamm...

5 months ago | 0

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Answered
ilaplace doesn't handle tanh()
You mean syms s T P2 = ilaplace( 1/s*(exp(s*T/4)-exp(-s*T/4))/(exp(s*T/4)+exp(s*T/4)) ,s); Tsteps = 0.1:0.5:20; num = vpa(su...

5 months ago | 1

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Fitting 8 equations simultaneously with three parameters
If all 8 equations are linear in the fitting parameters like in your example from above, "lsqlin" instead of "lsqnonlin" would b...

5 months ago | 2

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Answered
Partial Differential equation: Createpde. f as afunction
Take a look at the example "Coefficient Handle for Nonconstant Coefficients" under https://uk.mathworks.com/help/pde/ug/pde.p...

5 months ago | 0

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Neumann boundary condition in a diagonal matrix
For fun, I computed eigenvalues and eigenfunctions for the full region with boundary condition u = 0 and for the quarter region ...

5 months ago | 0

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Neumann boundary condition in a diagonal matrix
The Laplace operator is discretized as (u(x+h,y) - 2*u(x,y) + u(x-h,y))/h^2 + (u(x,y+h) - 2*u(x,y) + u(x,y-h))/h^2 If y = 0 an...

5 months ago | 0