Answered

Unusal error "Current use of the variable is inconsistent with its previous use or definition".

See how the +b is purple? That means MATLAB thinks you are invoking a as a function with +b as a character string input. Hence ...

Unusal error "Current use of the variable is inconsistent with its previous use or definition".

See how the +b is purple? That means MATLAB thinks you are invoking a as a function with +b as a character string input. Hence ...

7 months ago | 1

| accepted

Question

Incorrect datetime UTCLeapSeconds conversion

I am working with leap second data, and as part of the calculations I did this for a particular leap second: dt1 = datetime(197...

7 months ago | 1 answer | 0

Answered

How to add rows containing zeros to a matrix

E.g., one way using the end syntax: my_matrix = reshape(1:12,3,4) n = 4; % number of rows to append my_matrix(end+n,1) = 0 B...

How to add rows containing zeros to a matrix

E.g., one way using the end syntax: my_matrix = reshape(1:12,3,4) n = 4; % number of rows to append my_matrix(end+n,1) = 0 B...

7 months ago | 0

Answered

error using tranpose (recieving permute error )

If you are trying to transpose the initial 2D pages of your variable, you can do this: pagetranspose(featvales) Or this: d = ...

error using tranpose (recieving permute error )

If you are trying to transpose the initial 2D pages of your variable, you can do this: pagetranspose(featvales) Or this: d = ...

7 months ago | 0

Answered

Error L2 is not defined

You have a fundamental problem with your code. You have a 2nd order ODE, which means there will be two states you need to carry ...

Error L2 is not defined

You have a fundamental problem with your code. You have a 2nd order ODE, which means there will be two states you need to carry ...

7 months ago | 0

Answered

Use Indexing for more than 1 dimension of array simultaneously

Yet another way using linear indexing (showing what sub2ind( ) does internally): matrix = rand(10, 3); idx = [1; 2; 2; 3; 1; 2...

Use Indexing for more than 1 dimension of array simultaneously

Yet another way using linear indexing (showing what sub2ind( ) does internally): matrix = rand(10, 3); idx = [1; 2; 2; 3; 1; 2...

7 months ago | 0

Answered

Indexing and turning into column vector

Not really. It's going to be a two-step process no matter how you do it (without resorting to a mex routine, which isn't worth i...

Indexing and turning into column vector

Not really. It's going to be a two-step process no matter how you do it (without resorting to a mex routine, which isn't worth i...

8 months ago | 0

| accepted

Answered

how to make a single array out of 2 arrays

Just use indexing. E.g., odd=[0.4357, 0.78208,0.6245] even=[0.48004,1.29188,1.54668,0.82376] both(1:2:5) = odd both(2:2:8) =...

how to make a single array out of 2 arrays

Just use indexing. E.g., odd=[0.4357, 0.78208,0.6245] even=[0.48004,1.29188,1.54668,0.82376] both(1:2:5) = odd both(2:2:8) =...

8 months ago | 0

| accepted

Answered

Difference between 2 orientations

I would do your method #3 involving quaternions. This would give you the "smallest" rotation between the two attitudes. But you ...

Difference between 2 orientations

I would do your method #3 involving quaternions. This would give you the "smallest" rotation between the two attitudes. But you ...

8 months ago | 2

Answered

Implicit casting overhead from real to complex when multiplying two matrices

This is not a natively supported operation (to use your terms). Yes, the real matrix must be first upconverted to a complex matr...

Implicit casting overhead from real to complex when multiplying two matrices

This is not a natively supported operation (to use your terms). Yes, the real matrix must be first upconverted to a complex matr...

8 months ago | 1

Answered

why do we initialize any vector or matrices with zero.

If you know you will be filling in the variable elements downstream anyway, it would be faster to just allocate the memory and n...

why do we initialize any vector or matrices with zero.

If you know you will be filling in the variable elements downstream anyway, it would be faster to just allocate the memory and n...

8 months ago | 0

Answered

Complex matrix multiplication with pagemtimes

This really has nothing to do with the maturity of MATLAB ... every language that uses BLAS routines in the background will have...

Complex matrix multiplication with pagemtimes

This really has nothing to do with the maturity of MATLAB ... every language that uses BLAS routines in the background will have...

8 months ago | 2

| accepted

Answered

Matrix power vs for loop

Note that the A^endtime method is probably going to be more accurate as endtime gets larger. The loop method can have a tendancy...

Matrix power vs for loop

Note that the A^endtime method is probably going to be more accurate as endtime gets larger. The loop method can have a tendancy...

8 months ago | 0

Answered

error: matrix dimensions must agree

I would presume you may need element-wise operators. Try this: func = @(K_a,freq)(-K_a./(tan(2*pi*freq*h.*(1 + 0.19./((K_a/60 +...

error: matrix dimensions must agree

I would presume you may need element-wise operators. Try this: func = @(K_a,freq)(-K_a./(tan(2*pi*freq*h.*(1 + 0.19./((K_a/60 +...

9 months ago | 0

Answered

Average every 3 rows of 1 column in a 12 x 8 array

E.g., Data = [ 34 6 4 -6.60874766440390 -40.7725049965035 16217 0.289000000000000 1.02200000000000 35 6 5 -6.54326464...

Average every 3 rows of 1 column in a 12 x 8 array

E.g., Data = [ 34 6 4 -6.60874766440390 -40.7725049965035 16217 0.289000000000000 1.02200000000000 35 6 5 -6.54326464...

9 months ago | 0

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Answered

Converting 2D cell array to 3D matrix

E.g., MyCell = repmat({(1:4)'},2,3) % small sample data [m,n] = size(MyCell); reshape(cell2mat(MyCell(:)').',m,n,[]) size(an...

Converting 2D cell array to 3D matrix

E.g., MyCell = repmat({(1:4)'},2,3) % small sample data [m,n] = size(MyCell); reshape(cell2mat(MyCell(:)').',m,n,[]) size(an...

9 months ago | 1

| accepted

Answered

How can I calculate the "Median" of floating point numbers

E.g., x = randi(10,2,3) y = randi(10,2,3) z = randi(10,2,3) xyz = cat(3,x,y,z) result = median(xyz,3)

How can I calculate the "Median" of floating point numbers

E.g., x = randi(10,2,3) y = randi(10,2,3) z = randi(10,2,3) xyz = cat(3,x,y,z) result = median(xyz,3)

9 months ago | 0

| accepted

Answered

transposing 3d matrix with permute function

MATLAB does not store trailing singleton (1) dimensions beyond the 2nd dimension. Once you permute that 1 into the 3rd dimension...

transposing 3d matrix with permute function

MATLAB does not store trailing singleton (1) dimensions beyond the 2nd dimension. Once you permute that 1 into the 3rd dimension...

9 months ago | 2

Question

LU decomposition algorithm change

For this particular example: A=[ 1 2 3; 4 5 6; 7 8 9; 10 11 12]; I get two different results depending on...

9 months ago | 2 answers | 0

Answered

Inserting a double to a cell

E.g., x = randi(100,10,10) % sample data columns = [4,7]; % columns to check minx = min(x(:,columns)) % minimum of the two co...

Inserting a double to a cell

E.g., x = randi(100,10,10) % sample data columns = [4,7]; % columns to check minx = min(x(:,columns)) % minimum of the two co...

9 months ago | 0

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Answered

Using Matlab to solve 1D Schrödinger Equation (Strange Eigenfunctions)

Python: return is misspelled retrun The mL2V( ) function returns 1000*(y-1/2)**2 I don't see where y is defined prior to the ...

Using Matlab to solve 1D Schrödinger Equation (Strange Eigenfunctions)

Python: return is misspelled retrun The mL2V( ) function returns 1000*(y-1/2)**2 I don't see where y is defined prior to the ...

9 months ago | 0

Answered

1×0 empty double row vector using find

Welcome to the world of floating point arithmetic. For your specific example, they are not equal. E.g., x=[0 0.1 0.2 0.3 0.4 0....

1×0 empty double row vector using find

Welcome to the world of floating point arithmetic. For your specific example, they are not equal. E.g., x=[0 0.1 0.2 0.3 0.4 0....

9 months ago | 1

Answered

How to plot the first derivative of solution?

After the ode45( ) call, simply pass your x solution through your derivative function to obtain the xdot values. You can either ...

How to plot the first derivative of solution?

After the ode45( ) call, simply pass your x solution through your derivative function to obtain the xdot values. You can either ...

9 months ago | 0

Answered

optimizing: fastest way to detect if ANY points are within distance N of points?

Here is a naive brute force mex routine you can try out. It makes no attempts at cache optimization or multi-threading, and is p...

optimizing: fastest way to detect if ANY points are within distance N of points?

Here is a naive brute force mex routine you can try out. It makes no attempts at cache optimization or multi-threading, and is p...

10 months ago | 0

Answered

"roots" call is not providing the correct answer

Rename your old roots file (preferred method) or move it to a directory that is not on the MATLAB path. That way it won't shadow...

"roots" call is not providing the correct answer

Rename your old roots file (preferred method) or move it to a directory that is not on the MATLAB path. That way it won't shadow...

10 months ago | 1

Answered

How can ı solve this error ??Unable to perform assignment because the size of the left side is 1-by-5 and the size of the right side is 26-by-1.

You could expand the size of the LHS array. E.g., poles_real(i, 1:numel(roots_poly)) = real(roots_poly); poles_imag(i,...

How can ı solve this error ??Unable to perform assignment because the size of the left side is 1-by-5 and the size of the right side is 26-by-1.

You could expand the size of the LHS array. E.g., poles_real(i, 1:numel(roots_poly)) = real(roots_poly); poles_imag(i,...

10 months ago | 0

Answered

angle of a vector centered at a certain point

Once you have the vectors, you can calculate the angles between the vectors using the technique I posted here: https://www.math...

angle of a vector centered at a certain point

Once you have the vectors, you can calculate the angles between the vectors using the technique I posted here: https://www.math...

10 months ago | 0

Answered

How to expand dimension of a 2D array

All MATLAB trailing singleton (1) dimensions beyond the 2nd dimension are not physically stored, and will not show up in a size(...

How to expand dimension of a 2D array

All MATLAB trailing singleton (1) dimensions beyond the 2nd dimension are not physically stored, and will not show up in a size(...

10 months ago | 2

Answered

A single precision matrix multiplication problem

Somewhat related side comments: In general, the BLAS/LAPACK libraries do not contain mixed type argument routines. E.g., there ...

A single precision matrix multiplication problem

Somewhat related side comments: In general, the BLAS/LAPACK libraries do not contain mixed type argument routines. E.g., there ...

10 months ago | 2