John D'Errico
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comparison between two optimisation algorithms
There are very, very many ways to solve a computing problem. You have chosen one of them, and it worked for you. Is the choice...
comparison between two optimisation algorithms
There are very, very many ways to solve a computing problem. You have chosen one of them, and it worked for you. Is the choice...
4日 前 | 0
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Strange behaviour of plot
Cute. If you try this in R2025a: small = 1e-7;plot([0,small,1],[0,small,1]) small = 1e-8;plot([0,small,1],[0,small,1]) (Sorry...
Strange behaviour of plot
Cute. If you try this in R2025a: small = 1e-7;plot([0,small,1],[0,small,1]) small = 1e-8;plot([0,small,1],[0,small,1]) (Sorry...
5日 前 | 0
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How does Matlabs svd() function calculate the value of V?
UM, You seriously do not want to use X'*X to compute anything about the SVD. Yes, mathematically, it is the same. But this is no...
How does Matlabs svd() function calculate the value of V?
UM, You seriously do not want to use X'*X to compute anything about the SVD. Yes, mathematically, it is the same. But this is no...
6日 前 | 1
回答済み
icc rgb profile editing
You can use iccread and iccwrite. help iccread help iccwrite Having used iccread, you can modify whatever you wish, then writ...
icc rgb profile editing
You can use iccread and iccwrite. help iccread help iccwrite Having used iccread, you can modify whatever you wish, then writ...
6日 前 | 0
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How to reduce the file size of MAT files?
NO. Rounding numbers will change nothing. MATLAB does not store double precision numbers in decimal form. So even though you thi...
How to reduce the file size of MAT files?
NO. Rounding numbers will change nothing. MATLAB does not store double precision numbers in decimal form. So even though you thi...
12日 前 | 0
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select line by touching with mouse
"select curve?" Well, yes, in a sense. When you plot the curve, you can supply a ButtonDownFcn, so that when you click on the c...
select line by touching with mouse
"select curve?" Well, yes, in a sense. When you plot the curve, you can supply a ButtonDownFcn, so that when you click on the c...
12日 前 | 0
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Fitting a blackbody curve with two variables - having issues with lsqcurvefit stopping and unsure how to use options effectively
Your data does not seem to fit terribly well to the model you propose. c=2.998e8; h=6.6261e-34; kb=1.38e-23; %wavelgnth (x...
Fitting a blackbody curve with two variables - having issues with lsqcurvefit stopping and unsure how to use options effectively
Your data does not seem to fit terribly well to the model you propose. c=2.998e8; h=6.6261e-34; kb=1.38e-23; %wavelgnth (x...
13日 前 | 1
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How to generate all 2^n combinations of n choices from a 2-vector?
Simple enough. Don't use combinations. n = 3; t = dec2bin(0:2^n - 1) - '0' Easy enough to make that into a table if you so de...
How to generate all 2^n combinations of n choices from a 2-vector?
Simple enough. Don't use combinations. n = 3; t = dec2bin(0:2^n - 1) - '0' Easy enough to make that into a table if you so de...
16日 前 | 1
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Matlab 'try now' and contact customer service doesn't work
Answers is not customer support. In fact, we are generally not even employed at The MathWorks, though some TMW staff do visit th...
Matlab 'try now' and contact customer service doesn't work
Answers is not customer support. In fact, we are generally not even employed at The MathWorks, though some TMW staff do visit th...
18日 前 | 0
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is readmatrix a built-in Matlab function part over every install after 2019a?
NO. Not for ANY release number. Some of those functions may have been introduced in different years, different releases. And if ...
is readmatrix a built-in Matlab function part over every install after 2019a?
NO. Not for ANY release number. Some of those functions may have been introduced in different years, different releases. And if ...
19日 前 | 0
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Constraints to a Second Order Curve Fit
You want to constrain the quadratic coefficient to be positive. But your data wants it to be a little bit negative. Effectively,...
Constraints to a Second Order Curve Fit
You want to constrain the quadratic coefficient to be positive. But your data wants it to be a little bit negative. Effectively,...
約1ヶ月 前 | 1
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Is vectorization worth the trouble with recent MATLAB?
Is vectorization worth it? Let me see. For example: Add 1 to every element of a vector. V = rand(1,1e6); % Which is itself high...
Is vectorization worth the trouble with recent MATLAB?
Is vectorization worth it? Let me see. For example: Add 1 to every element of a vector. V = rand(1,1e6); % Which is itself high...
約1ヶ月 前 | 0
回答済み
How to specify intervals of increasing, decreasing of a function in MATLAB
This can get fairly messy, if your function is carefully designed to cause you problems. For example, you may need to find a sin...
How to specify intervals of increasing, decreasing of a function in MATLAB
This can get fairly messy, if your function is carefully designed to cause you problems. For example, you may need to find a sin...
約1ヶ月 前 | 1
回答済み
Not exactly the exact answer using Symbolic Math Toolbox
Your problem stems from a common mistake. Whaen you write this: syms t f = sin(t); frms = sqrt(1/(2*pi)*int(f^2,t,[0 2*pi]))...
Not exactly the exact answer using Symbolic Math Toolbox
Your problem stems from a common mistake. Whaen you write this: syms t f = sin(t); frms = sqrt(1/(2*pi)*int(f^2,t,[0 2*pi]))...
約1ヶ月 前 | 1
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How does the expfit function... functions
You may be confused. Well, let me say, almost certainly, you are confused. ;-) There is a difference between curve fitting, in ...
How does the expfit function... functions
You may be confused. Well, let me say, almost certainly, you are confused. ;-) There is a difference between curve fitting, in ...
約1ヶ月 前 | 0
回答済み
No results are showing in the symbolic math computation
First, you need to recognize MATLAB is case sensitive. Your code does not run, instead, it fails in several places. I fixed it, ...
No results are showing in the symbolic math computation
First, you need to recognize MATLAB is case sensitive. Your code does not run, instead, it fails in several places. I fixed it, ...
約1ヶ月 前 | 0
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Solving ODE just for one time step
Then I fail to see the problem. You want only the solution at the end point. % A simple ODE. with y(0) == 1, the analytical s...
Solving ODE just for one time step
Then I fail to see the problem. You want only the solution at the end point. % A simple ODE. with y(0) == 1, the analytical s...
約1ヶ月 前 | 0
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Analyzing errors of a numerical Jacobian matrix of partial derivatives, as the finite-differencing step-size gets successively smaller,
I explained EXACTLY this in my last answer to your last question. Please read what I write and think about it. If you don't then...
Analyzing errors of a numerical Jacobian matrix of partial derivatives, as the finite-differencing step-size gets successively smaller,
I explained EXACTLY this in my last answer to your last question. Please read what I write and think about it. If you don't then...
約1ヶ月 前 | 0
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How can I reduce the "method error" with my central-difference method, when estimating a Jacobian matrix of partial derivatives?
This is a complex question, with possibly no perfect answer. For example, suppose you have a Newton method, that employs a fini...
How can I reduce the "method error" with my central-difference method, when estimating a Jacobian matrix of partial derivatives?
This is a complex question, with possibly no perfect answer. For example, suppose you have a Newton method, that employs a fini...
約1ヶ月 前 | 3
回答済み
Better package manager abstracted away from matlab versions
Why don't they have the perfect set of tools, exactly as you want them to have been written? Because MATLAB was designed to make...
Better package manager abstracted away from matlab versions
Why don't they have the perfect set of tools, exactly as you want them to have been written? Because MATLAB was designed to make...
約1ヶ月 前 | 0
回答済み
Generate n random numbers between 0.1 and 0.9 without repetition
There are always many ways to solve a problem. Here is mine: % generate the set of ALL possible combinations. There are not man...
Generate n random numbers between 0.1 and 0.9 without repetition
There are always many ways to solve a problem. Here is mine: % generate the set of ALL possible combinations. There are not man...
約1ヶ月 前 | 0
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How to get real root of a function using fminbnd?
It sounds like you want to see the result: (-1)^(4/3) == 1 To do that, you want to use nthroot, by splitting the fraction...
How to get real root of a function using fminbnd?
It sounds like you want to see the result: (-1)^(4/3) == 1 To do that, you want to use nthroot, by splitting the fraction...
約2ヶ月 前 | 0
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solving numerically non-linear equation , code below does not work
What does not work? This is just a basic Newton-Raphson method. First, what are the functions for your test problem? x^2 + y...
solving numerically non-linear equation , code below does not work
What does not work? This is just a basic Newton-Raphson method. First, what are the functions for your test problem? x^2 + y...
約2ヶ月 前 | 1
回答済み
Find the range of duplicates in a sorted element
I'll create a longer vector, with a few duplicates. V0 = randi(8,[1,15]) V = sort(V0) Now you want to know where the dups liv...
Find the range of duplicates in a sorted element
I'll create a longer vector, with a few duplicates. V0 = randi(8,[1,15]) V = sort(V0) Now you want to know where the dups liv...
約2ヶ月 前 | 0
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What do you think of my numerical Jacobian, using the central-difference method?
What do we think of it? I'm sorry, but blech! Why? Don't number all of your variables! Don't create long lists of numbered var...
What do you think of my numerical Jacobian, using the central-difference method?
What do we think of it? I'm sorry, but blech! Why? Don't number all of your variables! Don't create long lists of numbered var...
約2ヶ月 前 | 1
回答済み
Inverting an 8x8 symbolic matrix
What nobody ever seems to understand is that a symbolic inverse of a matrix like this grows exponentially in complexity. Many th...
Inverting an 8x8 symbolic matrix
What nobody ever seems to understand is that a symbolic inverse of a matrix like this grows exponentially in complexity. Many th...
約2ヶ月 前 | 3
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Is there any precomputation step on A'*(.)*A if matrix A is known, to speed up matrix computation A'*B_i*A in matlab with B_i denpends on the previous matrix B_{i-1}.
A is known and fixed, and apparently large, else you would not care about speed. The amount of memory on your laptop is irrelev...
Is there any precomputation step on A'*(.)*A if matrix A is known, to speed up matrix computation A'*B_i*A in matlab with B_i denpends on the previous matrix B_{i-1}.
A is known and fixed, and apparently large, else you would not care about speed. The amount of memory on your laptop is irrelev...
約2ヶ月 前 | 0
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How to identify algorithm time complexity?
It is not at all trivial to determine the time complexity for SOME algorithms, at least not from merely knowing the method emplo...
How to identify algorithm time complexity?
It is not at all trivial to determine the time complexity for SOME algorithms, at least not from merely knowing the method emplo...
約2ヶ月 前 | 0
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Where to Find a Dataset of High-Quality MATLAB Code for Training an LLM?
Looking at your question a second time, it is about MATLAB in a sense. in that you are looking for a repository of code to train...
Where to Find a Dataset of High-Quality MATLAB Code for Training an LLM?
Looking at your question a second time, it is about MATLAB in a sense. in that you are looking for a repository of code to train...
約2ヶ月 前 | 0
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Logic Code required to be run in finite time
I think you misunderstand an important idea of computing. You NEVER want to use brute force on big problems. Those problems alwa...
Logic Code required to be run in finite time
I think you misunderstand an important idea of computing. You NEVER want to use brute force on big problems. Those problems alwa...
約2ヶ月 前 | 1
