John D'Errico
Retired
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已回答
Does inverse modelling is possible with ANFIS?
In general, absolutely no. This is impossible. Why do I say that? Consider even an absolutely trivial linear model. I don't need...
Does inverse modelling is possible with ANFIS?
In general, absolutely no. This is impossible. Why do I say that? Consider even an absolutely trivial linear model. I don't need...
3 days 前 | 0
已回答
Why is vpa not converting double accurately?
Quite interesting. When I first saw the title, I assumed it would be an obvious mistake. Then I saw the poster, and knew it woul...
Why is vpa not converting double accurately?
Quite interesting. When I first saw the title, I assumed it would be an obvious mistake. Then I saw the poster, and knew it woul...
4 days 前 | 1
| 已接受
已回答
finding partial solutions from ill-conditioned equations
The largest subset? It may be impossible to compute ANY subset accurately. You may be able to only compute a linear combination ...
finding partial solutions from ill-conditioned equations
The largest subset? It may be impossible to compute ANY subset accurately. You may be able to only compute a linear combination ...
7 days 前 | 0
已回答
What is evaluated to standard output is not being assigned to my variable
This is a not uncommon misunderstanding about cell arrays. d = {'.'; '..' '2022' '2024' '2025'} b = d(3:end) % the "righ...
What is evaluated to standard output is not being assigned to my variable
This is a not uncommon misunderstanding about cell arrays. d = {'.'; '..' '2022' '2024' '2025'} b = d(3:end) % the "righ...
13 days 前 | 1
| 已接受
已回答
Create similar curves through specific data points
The question is becoming more clear now, based on your response to my first answer. I'll post this as a separate answer, since t...
Create similar curves through specific data points
The question is becoming more clear now, based on your response to my first answer. I'll post this as a separate answer, since t...
22 days 前 | 0
| 已接受
已回答
Create similar curves through specific data points
You have asked a confusing question, which usually means you are yourself confused, perhaps about what you really want to do. It...
Create similar curves through specific data points
You have asked a confusing question, which usually means you are yourself confused, perhaps about what you really want to do. It...
23 days 前 | 0
已回答
Solving linear system modulo prime^n when matrix is univertable
You can't use LU anyway, since it is not designed to work on that problem. Nor can you use slash or backslash, which again, do n...
Solving linear system modulo prime^n when matrix is univertable
You can't use LU anyway, since it is not designed to work on that problem. Nor can you use slash or backslash, which again, do n...
25 days 前 | 0
已回答
Differentiating inside a matlab function
Oh, you were so close. Actually, you did not even need to tell diff what variable to differentiate with respect to. syms x(t) ...
Differentiating inside a matlab function
Oh, you were so close. Actually, you did not even need to tell diff what variable to differentiate with respect to. syms x(t) ...
26 days 前 | 0
已回答
How to generate an prime random number??
A random prime? Impossible to do. That is, something that many seem to misunderstand is you cannot generate a random number on s...
How to generate an prime random number??
A random prime? Impossible to do. That is, something that many seem to misunderstand is you cannot generate a random number on s...
28 days 前 | 0
已回答
How to make multiple lines of best fit into one scatter graph
Is it possible to do in MATLAB? Of course it is. It of course depends on the skill of the person writing the code. It depends on...
How to make multiple lines of best fit into one scatter graph
Is it possible to do in MATLAB? Of course it is. It of course depends on the skill of the person writing the code. It depends on...
28 days 前 | 0
已回答
Find best fit curve from multiple curves of different size
On the right end, you have an infinite slope. On the left end, not so much of a problem. But it will be better to do a couple of...
Find best fit curve from multiple curves of different size
On the right end, you have an infinite slope. On the left end, not so much of a problem. But it will be better to do a couple of...
28 days 前 | 0
已回答
How does interp1 work?
Why not post the actual data you used that caused the problem, instead of only a tiny fragment of it? You certainly CAN post t...
How does interp1 work?
Why not post the actual data you used that caused the problem, instead of only a tiny fragment of it? You certainly CAN post t...
29 days 前 | 2
已回答
Matlab Dimpulse function documentaion not found
It seems dimpulse (or at least one version thereof) can be found in the control TB. which dimpulse -all However, given the loc...
Matlab Dimpulse function documentaion not found
It seems dimpulse (or at least one version thereof) can be found in the control TB. which dimpulse -all However, given the loc...
29 days 前 | 0
已回答
part 3 example was wrong
Answers is not official MATLAB support. So telling us a problem exists does nothing. Contact support directly. https://www.ma...
part 3 example was wrong
Answers is not official MATLAB support. So telling us a problem exists does nothing. Contact support directly. https://www.ma...
1 month 前 | 1
已回答
I'm trying to find solutions to variables in a system of non linear eqations, that represent a geometrical puzzle.
A problem is, we don't actually know what is the geometric system you are trying to solve, nor have you told us the solution you...
I'm trying to find solutions to variables in a system of non linear eqations, that represent a geometrical puzzle.
A problem is, we don't actually know what is the geometric system you are trying to solve, nor have you told us the solution you...
1 month 前 | 0
已回答
Integrating a very long expression containing symbolic values
Is there some law of mathematics that everything you can or will write down has a solution? (No.) That int did not find a soluti...
Integrating a very long expression containing symbolic values
Is there some law of mathematics that everything you can or will write down has a solution? (No.) That int did not find a soluti...
1 month 前 | 0
已回答
Can someone help me fix my bisection function?
Good code. Well, at least in terms of the documentation. Excellent in that respect. Readable code is important when you need to ...
Can someone help me fix my bisection function?
Good code. Well, at least in terms of the documentation. Excellent in that respect. Readable code is important when you need to ...
1 month 前 | 0
| 已接受
已回答
What is the interpolation algorithm behind MATLAB’s pcolor with FaceColor = 'interp' that creates sharp, defined boundaries？
There are three simple ways to interpolate inside a 2-d rectangular region. But two of them are analogues of each other. First,...
What is the interpolation algorithm behind MATLAB’s pcolor with FaceColor = 'interp' that creates sharp, defined boundaries？
There are three simple ways to interpolate inside a 2-d rectangular region. But two of them are analogues of each other. First,...
1 month 前 | 0
已回答
How to compute the characteristic equation given the eigenvalues?
You have not asked this question as if it is a homework assignment, so I'll give an answer. The characteristic equation GIVEN e...
How to compute the characteristic equation given the eigenvalues?
You have not asked this question as if it is a homework assignment, so I'll give an answer. The characteristic equation GIVEN e...
1 month 前 | 0
| 已接受
已回答
How to download old version of toolbox?
You cannot. That is, you cannot use an old toolbox for a previous release in a newer release of MATLAB. So what can you do? You...
How to download old version of toolbox?
You cannot. That is, you cannot use an old toolbox for a previous release in a newer release of MATLAB. So what can you do? You...
1 month 前 | 0
已回答
Bug with large HEX numbers
H = 'fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141'; numel(H) So 64 hex digits, which would yield an intege...
Bug with large HEX numbers
H = 'fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141'; numel(H) So 64 hex digits, which would yield an intege...
1 month 前 | 1
已回答
How to get consistant results when testing code performance
A single time test will be susceptible to anything that attracts the attention of your CPU. And sadly, your CPU suffers from com...
How to get consistant results when testing code performance
A single time test will be susceptible to anything that attracts the attention of your CPU. And sadly, your CPU suffers from com...
1 month 前 | 0
已回答
update guess in fsolve
Um, no, You cannot always find a way to "update" your initial guess for fsolve. One can even prove this to be true. You can cha...
update guess in fsolve
Um, no, You cannot always find a way to "update" your initial guess for fsolve. One can even prove this to be true. You can cha...
1 month 前 | 1
已回答
How to remove columns in very large matrices.
GET MORE RAM!!!!!!!!! RAM IS CHEAP!!!!!!!! Need I say it again? You have a quite large array. (1.75e6*2000*8)/1e9 That arra...
How to remove columns in very large matrices.
GET MORE RAM!!!!!!!!! RAM IS CHEAP!!!!!!!! Need I say it again? You have a quite large array. (1.75e6*2000*8)/1e9 That arra...
1 month 前 | 1
已回答
using sparse matrix and vpa function simultaneously
I wanted a nice bright red Lambo for Christmas. Nope. Did not happen, nor was it ever going to happen. The same applies to you. ...
using sparse matrix and vpa function simultaneously
I wanted a nice bright red Lambo for Christmas. Nope. Did not happen, nor was it ever going to happen. The same applies to you. ...
1 month 前 | 0
| 已接受
已回答
Matrix is singular to working precision
I don't even need to run your code, to see an obvious mistake. In fact, I knew what I expect to be a problem, even before I look...
Matrix is singular to working precision
I don't even need to run your code, to see an obvious mistake. In fact, I knew what I expect to be a problem, even before I look...
1 month 前 | 0
已回答
real and integer variables
No. We won't do what is surely your homework assignment. But why not TRY IT! First, plotting it is trivial. LEARN TO USE a tool...
real and integer variables
No. We won't do what is surely your homework assignment. But why not TRY IT! First, plotting it is trivial. LEARN TO USE a tool...
2 months 前 | 0
已回答
Why matlab is not as intelligent as python
Why? Why is anything the case? Because it is. Because they are two different languages, with different capabilities, and differe...
Why matlab is not as intelligent as python
Why? Why is anything the case? Because it is. Because they are two different languages, with different capabilities, and differe...
2 months 前 | 3
已回答
Matlab sparse matrix does not come out as I would expect
S=sparse([1 3 2 1 4],[3 1 4 1 4],[1 2 3 4 5],4,4) full(S) It works just fine. What did you do wrong? LOOK CAREFULLY AT WHAT Y...
Matlab sparse matrix does not come out as I would expect
S=sparse([1 3 2 1 4],[3 1 4 1 4],[1 2 3 4 5],4,4) full(S) It works just fine. What did you do wrong? LOOK CAREFULLY AT WHAT Y...
2 months 前 | 1
| 已接受
已回答
defining upper and lower limits of a matrix
Is there any way to set the min and/or maximum values of the elements in a matrix, and do so automatically? NO. Well, not withou...
defining upper and lower limits of a matrix
Is there any way to set the min and/or maximum values of the elements in a matrix, and do so automatically? NO. Well, not withou...
2 months 前 | 1
