Answered

How to reduce computation time of (sparse) matrix multiplication in Matlab?

The answer is easy. It depends! What does it depend on? How sparse are your matrices? A lot of people think if half the entries...

How to reduce computation time of (sparse) matrix multiplication in Matlab?

The answer is easy. It depends! What does it depend on? How sparse are your matrices? A lot of people think if half the entries...

9 hours ago | 1

| accepted

Answered

How to plot only the real solutions of an implicit function ?

First, look at what you have. R = 0.35; L = 0.25; H = 0.4; syms x y F = sqrt(L^2-(R*(cosd(x)-sind(x).*sind(y))-H).^2) The ...

How to plot only the real solutions of an implicit function ?

First, look at what you have. R = 0.35; L = 0.25; H = 0.4; syms x y F = sqrt(L^2-(R*(cosd(x)-sind(x).*sind(y))-H).^2) The ...

1 day ago | 1

Answered

Two equations of two unknown angles

First, I would recognize that you PROBABLY intended 200 to be a number in DEGREES, not radians. (200 radians would seem to make ...

Two equations of two unknown angles

First, I would recognize that you PROBABLY intended 200 to be a number in DEGREES, not radians. (200 radians would seem to make ...

1 day ago | 0

| accepted

Answered

Producing a NaN only where there is a NaN, zero otherwise

I'm always amazed at how many ways there are to accomplish anything in MATLAB. Here was my effort. It took me some time to think...

Producing a NaN only where there is a NaN, zero otherwise

I'm always amazed at how many ways there are to accomplish anything in MATLAB. Here was my effort. It took me some time to think...

2 days ago | 1

Question

Producing a NaN only where there is a NaN, zero otherwise

This interesting question came up for me today. I was looking for a simple expression that can be used in a function handle, one...

2 days ago | 4 answers | 2

Answered

how to solve this question in Matlab

This is now, what, the third or 4th time you asked this question? The first few times, it was explicitly about your homework ass...

how to solve this question in Matlab

This is now, what, the third or 4th time you asked this question? The first few times, it was explicitly about your homework ass...

4 days ago | 0

| accepted

Answered

Reverse geometric progression algorithm

Since you want a symmetric set of points around 0, first generate a set on the positive side of the origin, then just flip them ...

Reverse geometric progression algorithm

Since you want a symmetric set of points around 0, first generate a set on the positive side of the origin, then just flip them ...

4 days ago | 0

| accepted

Answered

Matlab: Divide and Average Method

Its that new math. The supreme court redefined sqrt(4) as 1.68 just recently. So your code is correct. Now all we need to do is ...

Matlab: Divide and Average Method

Its that new math. The supreme court redefined sqrt(4) as 1.68 just recently. So your code is correct. Now all we need to do is ...

7 days ago | 0

Answered

How to tell if a function was called from within Matlab or from system?

Perhaps you might try what are essentially different calls, where you pass information about WHERE your call is coming from. So ...

How to tell if a function was called from within Matlab or from system?

Perhaps you might try what are essentially different calls, where you pass information about WHERE your call is coming from. So ...

7 days ago | 0

Answered

How can I slove the maxtric

You want to slove a matrix? Sorry. Valentines day was 3 days ago. Too late for s"love". A is a column vector, composed of the e...

How can I slove the maxtric

You want to slove a matrix? Sorry. Valentines day was 3 days ago. Too late for s"love". A is a column vector, composed of the e...

7 days ago | 0

Answered

Find an orthogonal vector

Never call a variable O. Consider how difficult it will be to find the bug one day, when you see or write a zero, instead of O. ...

Find an orthogonal vector

Never call a variable O. Consider how difficult it will be to find the bug one day, when you see or write a zero, instead of O. ...

8 days ago | 0

| accepted

Answered

Matlab does not show the curve equation in basic fitting

You misunderstand splines. A spline does not have a simple equation you can write down. And while in theory, you could write dow...

Matlab does not show the curve equation in basic fitting

You misunderstand splines. A spline does not have a simple equation you can write down. And while in theory, you could write dow...

9 days ago | 0

Answered

How do I determine the linear part of a force-displacement curve?

You have already accepted Star's answer, so you may not even see this answer. But in fact, there is no linear part of such a cur...

How do I determine the linear part of a force-displacement curve?

You have already accepted Star's answer, so you may not even see this answer. But in fact, there is no linear part of such a cur...

9 days ago | 0

Answered

Fitting data to a polar equation

@Omar Ashour It seems from this last comment that you re making some progress. There are some points I should make. First, wh...

Fitting data to a polar equation

@Omar Ashour It seems from this last comment that you re making some progress. There are some points I should make. First, wh...

11 days ago | 0

| accepted

Answered

why isn't determinant function working?

I think your problem may be due to the imaginary part of this rather nasty function. F = matlabFunction(DET1); F(1) ans = ...

why isn't determinant function working?

I think your problem may be due to the imaginary part of this rather nasty function. F = matlabFunction(DET1); F(1) ans = ...

11 days ago | 0

Answered

Fitting the data to power law using least square method

Let me look more carefully at your data, as there are some thigns that REALLY bother me about the approach you wish to use, as w...

Fitting the data to power law using least square method

Let me look more carefully at your data, as there are some thigns that REALLY bother me about the approach you wish to use, as w...

12 days ago | 0

Answered

Correspondence between optimization outputs and symbolic variables

The problem lies in your code. First, you have an obvious error in the code you show. I'll guess you just used too many or too f...

Correspondence between optimization outputs and symbolic variables

The problem lies in your code. First, you have an obvious error in the code you show. I'll guess you just used too many or too f...

12 days ago | 0

Answered

Which equation does Matlab use to fit a Normal distribution?

I think you misunderstand, as there are several things happening here. A normal distribution fit, that is, finding the paramete...

Which equation does Matlab use to fit a Normal distribution?

I think you misunderstand, as there are several things happening here. A normal distribution fit, that is, finding the paramete...

13 days ago | 1

Answered

How to search functions for mat use

You can use my mgrep function, downloadable form the file exchange. In your case, if you want to search for use of that file in...

How to search functions for mat use

You can use my mgrep function, downloadable form the file exchange. In your case, if you want to search for use of that file in...

13 days ago | 1

| accepted

Answered

Sparse of symbolic matrix

Sorry, but NO. Sparse storage does not applly to symbolic matrices. Even if it did, this would virtually not help you to speed ...

Sparse of symbolic matrix

Sorry, but NO. Sparse storage does not applly to symbolic matrices. Even if it did, this would virtually not help you to speed ...

13 days ago | 1

| accepted

Answered

Please explain how this matlab code works works and what it does

It can be almost impossible to figure out what undocumented code does, especially if we are not even told what it might be desig...

Please explain how this matlab code works works and what it does

It can be almost impossible to figure out what undocumented code does, especially if we are not even told what it might be desig...

14 days ago | 1

Answered

Confidence interval of regression line

If the line has KNOWN coefficients, then a confidence interval is meaningless. If you want to compute confidence intervals arou...

Confidence interval of regression line

If the line has KNOWN coefficients, then a confidence interval is meaningless. If you want to compute confidence intervals arou...

14 days ago | 0

| accepted

Answered

matrix retrieving given certain determinant

You want to generate a random matrix with a known determinant? n = 7; % The size of the matrix Dtarget = 12; % My target deter...

matrix retrieving given certain determinant

You want to generate a random matrix with a known determinant? n = 7; % The size of the matrix Dtarget = 12; % My target deter...

15 days ago | 0

Answered

Matrices with unknown elements multiplication

Define the eements of the matrices in terms of symbolic unknowns. Then use solve to determine the unknown elements. Note that un...

Matrices with unknown elements multiplication

Define the eements of the matrices in terms of symbolic unknowns. Then use solve to determine the unknown elements. Note that un...

15 days ago | 0

| accepted

Answered

How do i rotate a matrix over set of points.

No. You do not want to rotate a matrix. You have a list of points that lie in the plane, described as cooordinates in each colum...

How do i rotate a matrix over set of points.

No. You do not want to rotate a matrix. You have a list of points that lie in the plane, described as cooordinates in each colum...

15 days ago | 0

Answered

Is there a way to define a new built-in function?

As others have said, you need to start using your MATLAB search path. Once you put a file in your own personal search path, it w...

Is there a way to define a new built-in function?

As others have said, you need to start using your MATLAB search path. Once you put a file in your own personal search path, it w...

15 days ago | 1

Answered

Overdetermined Linear System with Binary-Solution

You CANNOT use lsqr on integer (binary) problems. Period. I don't know why you think you could do that. You cannot use intlinpr...

Overdetermined Linear System with Binary-Solution

You CANNOT use lsqr on integer (binary) problems. Period. I don't know why you think you could do that. You cannot use intlinpr...

17 days ago | 0

Answered

Help solving directional cosines

A=[-130.342, -75, -55; -75, -130.342, 65; -55, 65, -130.342]; svd(A) That small number as the third element of the s...

Help solving directional cosines

A=[-130.342, -75, -55; -75, -130.342, 65; -55, 65, -130.342]; svd(A) That small number as the third element of the s...

17 days ago | 1

| accepted

Answered

How to calculate error of trapz() function?

This is not a question about MATLAB, but a question about understanding numerical integration, and perhaps a bit of statistics. ...

How to calculate error of trapz() function?

This is not a question about MATLAB, but a question about understanding numerical integration, and perhaps a bit of statistics. ...

18 days ago | 1

Answered

Output result's format?

These are symbolic expressions you are showing. The format command has NOTHING to do with symbolic expressions. It applies only ...

Output result's format?

These are symbolic expressions you are showing. The format command has NOTHING to do with symbolic expressions. It applies only ...

19 days ago | 1

| accepted