How to fix "Error using indexing" while calculating differential equations?
The code you show will work perfectly in MATLAB, in literally any recent release of MATLAB. R2023 is entirely recent. However, ...

Writing a code to determine the gradient change in a profile
Your problem lies in this line: change_p = (abs(data.variable.gradpressure(i,j+1))-abs(data.variable.gradpressure(i,j)))/abs(da...

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Could MATLAB please provide rref() without the rational conversion?
Just look at the code. type rref Do you see the very last thing it does is do the conversion? Just write your own version that...

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Why does eig return different eigen values depending on whether eigen vector outputs are specified ?
Gosh, the eigenvalue questions are coming fast today. You have an 11x11 matrix. The eigenvalues of that matrix are equivalent to...

How to interprete an analytical eigendecomposition for a polynomial matrix with size nxn > 4x4 using the Symbolic Math Toolbox.
Ok, do you understand that you CANNOT compute the roots of a polynomial, if the degree of that polynomial is greater than 4? Wel...

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Strict inequalities are not supported (learn why)
It is NOT related to the release number. Sorry. That has nothing to do with it. This has been the case since release 0 of MATLAB...

Curve Fitter Polynomial Plots Strangely In Script
CONGRATULATIONS! You win an award for the one millionth person to make this mistake! Your award is a free trip to the fabled vac...

Why is indexing a sparse matrix not behaving how I would expect?
This is not a question about sparse matrices. Well, it is, but it is not really. Sparse matrices are exactly the same as any oth...

how to write the right code to measure the elapsed time of this method d1 = diag(1./diag(A))
Why do you care? The computations will be almost inifinitessimal, even for a huge matrix. (Do you understand the notation O(n)?)...

Alternative to interp2
Perhaps you are calling interp2 multiple times in a loop, when a single call with multiple points will be far faster. This would...

How can people who are bad at math and have no programming aptitude learn MATLAB? (Long question)
An old question, one that surely would be better placed in a discussion, now that we have them. However, as soon as someone dec...

Someone that works with symbolic variables?
When k is even slightly large (apparently 4 is large enough) things go to hell. Did I not answer this question before? I know I ...

using polyval with one of the polynomials of a spline obtained with the unmkpp command, the results do not overlap! Why?
@David Goodmanson and @dpb and @Steven Lord have all said the polynomial segments are intended to be LOCAL with respect to the b...

Problems with code with symbolic variables.
No. I won't consult by gmail, or whatever. But there is no need. Even for k==2, what do I see? eqn = [3*c1^2 + 3*c3 == 0, 3*c...

MATLAB Programming Techniques, Extracting Portions of a table
Why do you need it? Well, I don't see the question in the course, and I am not enrolled in the course, so... But what does that...

I want show population on plot like 36M, 37M....
You want the plot to plot each point as a string like 36M, 38M, etc? Why not just divide by 1e6, then use the axis label to ind...

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Why are the components of the two eigenvectors not continuous and smooth, when the underlying data is continuous and smooth?
You can think of the eigenvalues (and assiciated eigenvectors) as coming from the roots of a polynomial. In fact, they do exactl...

How to interpolate values given a starting and end point
If you ONLY have two data points, the only possible interpolation is LINEAR. There is no fancy method to interpolate in a nonlin...

Syntax for specifying boundary condition using dsolve.
Your beam is fixed in position at the left end, as is the slope at that point. At the right end, you have fixed the location, b...

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How to use fminsearch for vectors
I think your problem is you are confused. And your confusion turns into a highly confusing question. Questions like is the optim...

How to Reduce Oscillations (not noise) in a Signal?
To me, the upper signal looks like the convolution of something like a sinc with the lower signal. And that would mean, IF you k...

2ヶ月 前 | 0

How to find the intersection of linear regression model and yline
Pretty boring data. T(:,1) = [0 1 2 3 4 5]; T(:,2) = [0 1 2 3 4 5]; P = polyfit(T(:,1),T(:,2),1) a = P(1) b = P(2) They...

2ヶ月 前 | 0

Issue with solving ill-conditioned symbolic DAE system
You have a DAE, with a linear constraint system that happens to be ill-conditioned. I would try reducing the constraint system. ...

2ヶ月 前 | 0

inv(A)*B*inv(A) or A\B/A, which is more accurate for a full rank A and half rank B
Why would you want to compute the inverse of A TWICE ANYWAY? Even using both slash and backslash is arguably a bad idea, since a...

2ヶ月 前 | 0

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Finding accurate inverse of binary circulant matrix
Gosh. I thought that multiplying a matrix by its inverse gives an identity matrix. :) A = readmatrix('MixingLayer.xlsx','sheet'...

2ヶ月 前 | 0

Doing a Matlab update without charging
Is it a bad thing? Only in the sense that if your computer suddenly dies in the middle, the software may now be in a spot where ...

2ヶ月 前 | 0

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Not able to plot a proper graph for the equation.
syms x y = (1*1*((25)-(x.^2)))/((x.^4)-((x.^2)*((1*(1.78))+(25)+1))+(1*(25))) First, where are the poles? A pole lives where t...

2ヶ月 前 | 0

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How to find solution to system of 2 circle equations in Matlab?
Torsten has answered your question perfectly well, I think. No solution exists for that problem as posed. But suppose you had a ...

2ヶ月 前 | 0

How to colour a portion of a curve by red and remaining by black
Plot it as TWO curves, both on the same figure, one in red, one in black. Use the hold command between the two calls to plot, s...

2ヶ月 前 | 0

Solve an ODE on a torus
Simple enough. Just transform the problem. So if [u,v] live on [0,1]x[0,1], then s = (cos(2*pi*u)+1)/2 t = (cos(2*pi*v...

2ヶ月 前 | 0