Answered

inverse matrix calculation problem

You need to understand that the matrix a=[1 2 3;4 5 6;7 8 9] is singular. Therefore it has no inverse. You may as well have s...

inverse matrix calculation problem

You need to understand that the matrix a=[1 2 3;4 5 6;7 8 9] is singular. Therefore it has no inverse. You may as well have s...

14 hours ago | 0

Answered

Matlab code for fractions

Confusing question. Do you know the value of s? s = 7 s = 7 >> 1.5/s ans = 0.214285714285714 >> format rat...

Matlab code for fractions

Confusing question. Do you know the value of s? s = 7 s = 7 >> 1.5/s ans = 0.214285714285714 >> format rat...

1 day ago | 1

Answered

Direction between points from [0,360]

The function atan2d gives angles that are from -180 to 180. Not a problem. This works: mod(atan2d(y,x),360) But you want the a...

Direction between points from [0,360]

The function atan2d gives angles that are from -180 to 180. Not a problem. This works: mod(atan2d(y,x),360) But you want the a...

3 days ago | 2

| accepted

Answered

PLEASE HELP ME CONVERT THIS EQUATION TO MATLAB CODE

Well, you did make an effort, and it was pretty close. But did you read my response? Did you read the help for tand and cosd? W...

PLEASE HELP ME CONVERT THIS EQUATION TO MATLAB CODE

Well, you did make an effort, and it was pretty close. But did you read my response? Did you read the help for tand and cosd? W...

4 days ago | 0

| accepted

Answered

Exponential Piecewise function creation.

A spline is not a piecewise exponential function, so using spline directly would be a waste of time, IF you truly need a piecewi...

Exponential Piecewise function creation.

A spline is not a piecewise exponential function, so using spline directly would be a waste of time, IF you truly need a piecewi...

4 days ago | 1

| accepted

Answered

minimum value of one inequality

This is just mathematics. r = 0.001; s = 7; n ALWAYS appears as 2^(-n/2). So calling that number x, first write the problem ...

minimum value of one inequality

This is just mathematics. r = 0.001; s = 7; n ALWAYS appears as 2^(-n/2). So calling that number x, first write the problem ...

5 days ago | 4

| accepted

Answered

Generate random sequence number with condition

I think you still do not appreciate that you cannot just say something is "random" and not define the distribution. For exampl...

Generate random sequence number with condition

I think you still do not appreciate that you cannot just say something is "random" and not define the distribution. For exampl...

5 days ago | 1

Answered

error using cross (A and B must have at least one dimension of length 3.)

I'm not sure what you want in terms of a 25000 dimensional cross produt between two vectors. What do you think it means? After a...

error using cross (A and B must have at least one dimension of length 3.)

I'm not sure what you want in terms of a 25000 dimensional cross produt between two vectors. What do you think it means? After a...

6 days ago | 1

| accepted

Answered

Diagonalising a Skew-Symmetric Matrix

Matrices that are defective will not have a complete set of eigenvectors. https://en.wikipedia.org/wiki/Defective_matrix " In...

Diagonalising a Skew-Symmetric Matrix

Matrices that are defective will not have a complete set of eigenvectors. https://en.wikipedia.org/wiki/Defective_matrix " In...

6 days ago | 0

Answered

Molecules on flat surface by using the package of Atomistic Topology Operations

Without more carefully reading the help for the code you are using, when I go to that link, it describes Box_dim as a variable. ...

Molecules on flat surface by using the package of Atomistic Topology Operations

Without more carefully reading the help for the code you are using, when I go to that link, it describes Box_dim as a variable. ...

6 days ago | 0

Answered

Taylor polynomial of a not infinitely differentiable function.

Your question has absolutely nothing to do with MATLAB, but you seem to have made some effort. So I will point out that you may ...

Taylor polynomial of a not infinitely differentiable function.

Your question has absolutely nothing to do with MATLAB, but you seem to have made some effort. So I will point out that you may ...

7 days ago | 1

| accepted

Answered

Numerical integration over (0, x1)

If t is unknown, then you need to use symbolic tools to do the integration. syms x t K = 1/((exp(0.014342/(x * t)) - 1)) * (1/...

Numerical integration over (0, x1)

If t is unknown, then you need to use symbolic tools to do the integration. syms x t K = 1/((exp(0.014342/(x * t)) - 1)) * (1/...

7 days ago | 1

| accepted

Answered

How can i compute an interpolated curve?

You don't provide the actual data. But you are asking to do something which is trivially easy for the eye to do, more difficult ...

How can i compute an interpolated curve?

You don't provide the actual data. But you are asking to do something which is trivially easy for the eye to do, more difficult ...

7 days ago | 1

| accepted

Answered

how can I draw half circle in matlab ?

Sigh. You DID make an effort. It is not even a terrible solution, though what you did will not work, since it will at best be a ...

how can I draw half circle in matlab ?

Sigh. You DID make an effort. It is not even a terrible solution, though what you did will not work, since it will at best be a ...

8 days ago | 2

| accepted

Answered

linprog cannot find solution

While you claim a solution exists, initially, I sincerely wonder if it truly does. I may learn differently by the time I am done...

linprog cannot find solution

While you claim a solution exists, initially, I sincerely wonder if it truly does. I may learn differently by the time I am done...

8 days ago | 1

Answered

How to Run PSO with Real Data

You can't. That is, the optimal is just the optimal value at each point in your sample. You cannot do better than that, at least...

How to Run PSO with Real Data

You can't. That is, the optimal is just the optimal value at each point in your sample. You cannot do better than that, at least...

9 days ago | 0

Answered

How to solve for x in an sin equation?

No. There are INFINITELY many solutions. So you cannot say you want the OTHER solution. You can simply enough find a positive so...

How to solve for x in an sin equation?

No. There are INFINITELY many solutions. So you cannot say you want the OTHER solution. You can simply enough find a positive so...

10 days ago | 0

| accepted

Answered

linearly independent eigen vectors

And for some strange reason, you think that eig as applied to a diagonal matrix does not produce a set of independent eigenvecto...

linearly independent eigen vectors

And for some strange reason, you think that eig as applied to a diagonal matrix does not produce a set of independent eigenvecto...

10 days ago | 0

| accepted

Answered

How can large sparse matrix (Y bus matrix of order 800*800) be done inverse in Matlab?

An 800 by 800 matrix is barely what I would call large anymore. Perhaps 40 years ago, yes. Today, it is almost tiny. Ok, not tin...

How can large sparse matrix (Y bus matrix of order 800*800) be done inverse in Matlab?

An 800 by 800 matrix is barely what I would call large anymore. Perhaps 40 years ago, yes. Today, it is almost tiny. Ok, not tin...

11 days ago | 0

| accepted

Answered

How to subtract from a vector array and, if the answer is lees than 0, have it return a value of 0

Simple. No need to test anything either. Just use the max function. x = [1 2 3]; x(1) = max(x(1) - 2,0); x x = 0 ...

How to subtract from a vector array and, if the answer is lees than 0, have it return a value of 0

Simple. No need to test anything either. Just use the max function. x = [1 2 3]; x(1) = max(x(1) - 2,0); x x = 0 ...

13 days ago | 0

Answered

Calculate factorial with 2 variables

Why do you feel you need to use loops? You should never write your own code for something that is far better computed using an e...

Calculate factorial with 2 variables

Why do you feel you need to use loops? You should never write your own code for something that is far better computed using an e...

13 days ago | 2

Answered

Random number from 1 to 100 if the number between 20 to 30 add 100 if the number 50 to 60 minus 100.

I'll generate 10 samples. N = 10; X = randi(100,1,N); ind = (X >= 20) & (X <= 30); X(ind) = X(ind) + 100; ind = (X >= 5...

Random number from 1 to 100 if the number between 20 to 30 add 100 if the number 50 to 60 minus 100.

I'll generate 10 samples. N = 10; X = randi(100,1,N); ind = (X >= 20) & (X <= 30); X(ind) = X(ind) + 100; ind = (X >= 5...

15 days ago | 0

Answered

Curve Fitting and Distribution Fitting

You have what, 13 data points? A model with many exponents in it? A model that is surely based on no real physical meaning of th...

Curve Fitting and Distribution Fitting

You have what, 13 data points? A model with many exponents in it? A model that is surely based on no real physical meaning of th...

17 days ago | 0

Answered

Integral of bessel function returns all zeros

It is a really bad idea to use gamma as a variable name because you are now stepping on the name of a very useful function in MA...

Integral of bessel function returns all zeros

It is a really bad idea to use gamma as a variable name because you are now stepping on the name of a very useful function in MA...

18 days ago | 0

| accepted

Answered

Sampling data using contraints

Use my randFixedLinearCombination tool, as found on the file exchange. (I did just post an update today, fixing a bug the code t...

Sampling data using contraints

Use my randFixedLinearCombination tool, as found on the file exchange. (I did just post an update today, fixing a bug the code t...

18 days ago | 1

| accepted

Submitted

randFixedLinearCombination

Uniform random samples over a n-dimensional hyper-rectangle, subject to a linear equality constraint

18 days ago | 7 downloads |

Answered

recursive function to check a Palindrome

Why not try? I won't write it for you, as the entire problem is to make you think. I'll give you one hint, and I will hope nobod...

recursive function to check a Palindrome

Why not try? I won't write it for you, as the entire problem is to make you think. I'll give you one hint, and I will hope nobod...

18 days ago | 1

Answered

Constructing a Maze with vectors

Insert NaNs between eack block of lines. X = [x,nan,x1,nan,x2]; Y = [y,nan,y1,nan,y2]; Now the various sets of line segments ...

Constructing a Maze with vectors

Insert NaNs between eack block of lines. X = [x,nan,x1,nan,x2]; Y = [y,nan,y1,nan,y2]; Now the various sets of line segments ...

18 days ago | 1

| accepted

Answered

How to solve exponential equations.

Thank you for posting this as a question instead of an answer. The simplest way to solve this is if you have the curve fitting ...

How to solve exponential equations.

Thank you for posting this as a question instead of an answer. The simplest way to solve this is if you have the curve fitting ...

19 days ago | 0

Answered

creating a repeating diagonal matrix

You want to repeat that sequence on the main diagonal? v = [4 1 0 1]; A = diag(repmat(v,1,25)); That is, use repmat to replic...

creating a repeating diagonal matrix

You want to repeat that sequence on the main diagonal? v = [4 1 0 1]; A = diag(repmat(v,1,25)); That is, use repmat to replic...

20 days ago | 0

| accepted