John D'Errico
Statistica
All
MATLAB Answers
File Exchange
62 File
Cody DiscussionsRANK
9
of 301.973
REPUTAZIONE
22.313
CONTRIBUTI
15 Domande
7.938 Risposte
ACCETTAZIONE DELLE RISPOSTE
46.67%
VOTI RICEVUTI
4.876
RANK
4 of 21.476
REPUTAZIONE
66.889
VALUTAZIONE MEDIA
4.80
CONTRIBUTI
62 File
DOWNLOAD
272
ALL TIME DOWNLOAD
604007
CONTRIBUTI
0 Post
CONTRIBUTI
0 Pubblico Canali
VALUTAZIONE MEDIA
CONTRIBUTI
14 Punti principali
NUMERO MEDIO DI LIKE
3
Feeds
Risposto
What exactly does ε represent in numerical computing
Just to add some more info... For example, pi(x) is known as the prime counting function to some, the number of primes less tha...
What exactly does ε represent in numerical computing
Just to add some more info... For example, pi(x) is known as the prime counting function to some, the number of primes less tha...
4 giorni fa | 0
Risposto
Why does parfor slow down with large shared arrays?
I can't test this myself, and I lack a great understanding of the parallel tools. But it looks like there are a few issues, main...
Why does parfor slow down with large shared arrays?
I can't test this myself, and I lack a great understanding of the parallel tools. But it looks like there are a few issues, main...
5 giorni fa | 0
Risposto
How to get abbreviations into vars?
Can you just exclude a term just by looking at it, without knowing the parameters in it? Given the complexity of the mess you ha...
How to get abbreviations into vars?
Can you just exclude a term just by looking at it, without knowing the parameters in it? Given the complexity of the mess you ha...
9 giorni fa | 0
Risposto
Why is vecnorm So Slow?
The jump is often a question of algorithm changes. You would be surprised how often algorithms exhibit nonlinear breaks. As I re...
Why is vecnorm So Slow?
The jump is often a question of algorithm changes. You would be surprised how often algorithms exhibit nonlinear breaks. As I re...
11 giorni fa | 1
Risposto
HDL coder support for Microchip high level synthesis tool SmartHLS
I'm sorry, but Answers is not a team. And we have no access to any information about timelines or any knowledge of when a given ...
HDL coder support for Microchip high level synthesis tool SmartHLS
I'm sorry, but Answers is not a team. And we have no access to any information about timelines or any knowledge of when a given ...
16 giorni fa | 0
Risposto
why does factor(1) return 1? shouldn't it return null?
Yes, I agree, in that f1 = factor(1) could arguably return empty. 1 is not indeed prime, and so the result is inconsistent wit...
why does factor(1) return 1? shouldn't it return null?
Yes, I agree, in that f1 = factor(1) could arguably return empty. 1 is not indeed prime, and so the result is inconsistent wit...
22 giorni fa | 0
Risposto
solve() returning empty, does a solution exist?
Just because solve returns empty does not mean a solution does not exist. In fact, most relations you can write down have absolu...
solve() returning empty, does a solution exist?
Just because solve returns empty does not mean a solution does not exist. In fact, most relations you can write down have absolu...
27 giorni fa | 1
| accettato
Risposto
Saving my path for future sessions.
The trick here is to use the help, because it teaches you what to use, at least it gives you a hint at how to solve it. If you m...
Saving my path for future sessions.
The trick here is to use the help, because it teaches you what to use, at least it gives you a hint at how to solve it. If you m...
29 giorni fa | 0
Risposto
Help using the toeplitz function
20x20 is not large by any measure I would ever imagine. 20000x20000 might be large. :) Of course, large is a purely subjective a...
Help using the toeplitz function
20x20 is not large by any measure I would ever imagine. 20000x20000 might be large. :) Of course, large is a purely subjective a...
circa un mese fa | 0
| accettato
Risposto
MATLAB Randomly Changes Values in Array to Scientific Notation
It is literally a certainty that some of those values are only approximately integer. No question in my mind. And is certainly n...
MATLAB Randomly Changes Values in Array to Scientific Notation
It is literally a certainty that some of those values are only approximately integer. No question in my mind. And is certainly n...
circa un mese fa | 0
| accettato
Risposto
How to call kummerU for a stand alone program
You cannot do it from MATLAB, as stated by others. However, it looks like python does offer similar functionality. And I believe...
How to call kummerU for a stand alone program
You cannot do it from MATLAB, as stated by others. However, it looks like python does offer similar functionality. And I believe...
circa un mese fa | 0
Risposto
Can I solve a symetric system using only the lower triangular portion of the matrix?
You don't show your matrix. Only a picture of it, and a picture is not quite worth a thousand words all of the time. ;-) But co...
Can I solve a symetric system using only the lower triangular portion of the matrix?
You don't show your matrix. Only a picture of it, and a picture is not quite worth a thousand words all of the time. ;-) But co...
circa 2 mesi fa | 0
Risposto
free trail doubt issue
After it ends in 30 days, it will just end. You will have a choice then of continuing your use of MATLAB by paying the normal fe...
free trail doubt issue
After it ends in 30 days, it will just end. You will have a choice then of continuing your use of MATLAB by paying the normal fe...
circa 2 mesi fa | 0
Risposto
Volume and Surface Area of a Compound Geometric Object
First, alpha shapes tend to be poor at representing volumes with sharp internal corners, like those between the intersection of ...
Volume and Surface Area of a Compound Geometric Object
First, alpha shapes tend to be poor at representing volumes with sharp internal corners, like those between the intersection of ...
circa 2 mesi fa | 1
Risposto
Call parameters by their variable name in Simulink rather than having to index the value.
If you can pass in a vector, then you can pass in a structure. Just assign fields to the structure. parameters.khch = 2; There...
Call parameters by their variable name in Simulink rather than having to index the value.
If you can pass in a vector, then you can pass in a structure. Just assign fields to the structure. parameters.khch = 2; There...
circa 2 mesi fa | 0
Risposto
looking for creator of specific code
The codes I did find were a bit more sophisticated in general, and I did not expect to find anything. HOWEVER, when I looked on ...
looking for creator of specific code
The codes I did find were a bit more sophisticated in general, and I did not expect to find anything. HOWEVER, when I looked on ...
circa 2 mesi fa | 1
Risposto
¿Cómo podría solucionar matrices por el comando [L,U]? no sé nada respecto al tema
I think your confusion stems from a misunderstanding. LU is fine, even with rank deficient matrices. As long as you use the MATL...
¿Cómo podría solucionar matrices por el comando [L,U]? no sé nada respecto al tema
I think your confusion stems from a misunderstanding. LU is fine, even with rank deficient matrices. As long as you use the MATL...
2 mesi fa | 0
Risposto
Convergence error in numerical method.
99,9% probable user error, 0.1%, it could be real. Hey we cannot know, since we don't see your code. But the point is, you hav...
Convergence error in numerical method.
99,9% probable user error, 0.1%, it could be real. Hey we cannot know, since we don't see your code. But the point is, you hav...
2 mesi fa | 1
Risposto
Minimally constraining an FEA Model in Matlab
If it is resting on a surface, it is not resting gently, in the sense that it CANNOT freely expand below the surface. In fact, y...
Minimally constraining an FEA Model in Matlab
If it is resting on a surface, it is not resting gently, in the sense that it CANNOT freely expand below the surface. In fact, y...
3 mesi fa | 0
| accettato
Risposto
Find specified number of points on curve with identical chord length (not arc length)
Admittedly, interparc does not solve the problem you want to solve. At least, not the probem you CLAIM you want to solve. As the...
Find specified number of points on curve with identical chord length (not arc length)
Admittedly, interparc does not solve the problem you want to solve. At least, not the probem you CLAIM you want to solve. As the...
3 mesi fa | 0
Risposto
can this code be improved?
You have asked several questions. 1. Is it well written? 2. Can it be improved? Something you did not ask is if it SHOULD be imp...
can this code be improved?
You have asked several questions. 1. Is it well written? 2. Can it be improved? Something you did not ask is if it SHOULD be imp...
3 mesi fa | 0
Risposto
Eigendecomposition not fully utilizing all cores on M1 pro, matlab 2025b
Some operations are not as easily parallelized when utilizing automatic mutithreading. That is possibly the case for eig, where ...
Eigendecomposition not fully utilizing all cores on M1 pro, matlab 2025b
Some operations are not as easily parallelized when utilizing automatic mutithreading. That is possibly the case for eig, where ...
4 mesi fa | 0
| accettato
Risposto
I want to decrease the time my Script
If you want to speed up your code, then you need to make the effort. We cannot possibly know what you are doing here, at least n...
I want to decrease the time my Script
If you want to speed up your code, then you need to make the effort. We cannot possibly know what you are doing here, at least n...
4 mesi fa | 0
| accettato
Risposto
Why Does polyval Return Zero When the Coefficients are Empty?
(This could easily better belong in a discussion than in Answers.) I could argue that any choice they made was arbitrary, becau...
Why Does polyval Return Zero When the Coefficients are Empty?
(This could easily better belong in a discussion than in Answers.) I could argue that any choice they made was arbitrary, becau...
4 mesi fa | 0
Discussion
Little Fermat, a valuable tool for primality testing
In a previous discussion, https://www.mathworks.com/matlabcentral/discussions/tips/884294-oh-no-isprime-is-missing-just-kidding...
4 mesi fa | 0
Risposto
GA stops with different score every time, even with setting big MaxGeneations and MaxStallGenerations
Nonlinear solvers, of which GA is one, cannot be forced to ALWAYS return the optimal result. And while tools like GA are designe...
GA stops with different score every time, even with setting big MaxGeneations and MaxStallGenerations
Nonlinear solvers, of which GA is one, cannot be forced to ALWAYS return the optimal result. And while tools like GA are designe...
4 mesi fa | 1
Risposto
Does [V,D] = eig(A) always return normalized eigenvectors for any real matrix A?
Be a little careful that A is not in symbolic form, even if it is real and SPD. A = randn(4,3); A = A'*A % A MUST clearly be SP...
Does [V,D] = eig(A) always return normalized eigenvectors for any real matrix A?
Be a little careful that A is not in symbolic form, even if it is real and SPD. A = randn(4,3); A = A'*A % A MUST clearly be SP...
4 mesi fa | 1
Risposto
Is fit() deterministic when StartPoint is specified?
If the start point is specified, then yes, FIT should be deterministic. At that point there is no reason for any pseudo-random n...
Is fit() deterministic when StartPoint is specified?
If the start point is specified, then yes, FIT should be deterministic. At that point there is no reason for any pseudo-random n...
4 mesi fa | 2
Discussion
What is an emirp? Can we find a new world record size prime of this form, using only MATLAB, and a home computer?
An emirp is a prime that is prime when viewed in in both directions. They are not too difficult to find at a lower level. For ex...
4 mesi fa | 0
Risposto
fread a double that's been broken up into four 16 bit words
I don't see the problem. For example... Xtest = randn*100 Now, I'll split it into 4 hex numbers, each taking up 16 bits. Xhe...
fread a double that's been broken up into four 16 bit words
I don't see the problem. For example... Xtest = randn*100 Now, I'll split it into 4 hex numbers, each taking up 16 bits. Xhe...
4 mesi fa | 0
