General interest: interdisciplinary approaches to complex problems (in particular mixing Mathematics, Physics, and Computer science).

Answered

how is imwrite() in Matlab2020a saving RGB?

You are saving as a jpeg file, which is lossy by default. If you save as .png for example (lossless), there will be no differen...

how is imwrite() in Matlab2020a saving RGB?

You are saving as a jpeg file, which is lossy by default. If you save as .png for example (lossless), there will be no differen...

9 months ago | 0

Answered

Can't call function within class

You forgot to bracket the output args, and the semi-column is useless: function [resamp_x,resamp_y] = resamp_sig(obj)

Can't call function within class

You forgot to bracket the output args, and the semi-column is useless: function [resamp_x,resamp_y] = resamp_sig(obj)

9 months ago | 0

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Answered

Matlab: Select a variable name and find the corresponding value

Here is one way: content = fileread( 'myTextFile.txt' ) ; match = regexp( content, '(?<=\$_Wk1_lr_m,\s+str\s*=\s*''\s*)[^\s'...

Matlab: Select a variable name and find the corresponding value

Here is one way: content = fileread( 'myTextFile.txt' ) ; match = regexp( content, '(?<=\$_Wk1_lr_m,\s+str\s*=\s*''\s*)[^\s'...

9 months ago | 0

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Answered

video in a figure

The reason is indicated in the doc: "The movie function uses a default figure size of 560-by-420 and does not resize figures to ...

video in a figure

The reason is indicated in the doc: "The movie function uses a default figure size of 560-by-420 and does not resize figures to ...

11 months ago | 0

Answered

I have been getting error 377 for weeks now. How do I fix this issue?

You could follow the instructions for manual activation provided in the thread referenced in this answer.

I have been getting error 377 for weeks now. How do I fix this issue?

You could follow the instructions for manual activation provided in the thread referenced in this answer.

11 months ago | 0

Answered

extract data from EEG text file

Using the data text file that you provided elsewhere (renamed and attached to this answer), here is a short example of one way t...

extract data from EEG text file

Using the data text file that you provided elsewhere (renamed and attached to this answer), here is a short example of one way t...

1 year ago | 1

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Answered

How to sum repeated adjacent values in a vector

Here is one way: Y = splitapply( @sum, X, [0, cumsum( diff(X) ~= 0 )] + 1 ) ; or, split into two expressions that make it easi...

How to sum repeated adjacent values in a vector

Here is one way: Y = splitapply( @sum, X, [0, cumsum( diff(X) ~= 0 )] + 1 ) ; or, split into two expressions that make it easi...

1 year ago | 2

Answered

Comparing Data sets with same numbers of Array

As you have no N-NE direction, here is an example for SE-S: dayId = [1, 5, 10, 15, 50, 60, 92] ; cat_sub = cat_wind_direct...

Comparing Data sets with same numbers of Array

As you have no N-NE direction, here is an example for SE-S: dayId = [1, 5, 10, 15, 50, 60, 92] ; cat_sub = cat_wind_direct...

1 year ago | 0

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Answered

How do I extract points from multiple circles?

We cannot test without your data, but the approach seems fine. You could use the PDIST2 function and extract everything in one s...

How do I extract points from multiple circles?

We cannot test without your data, but the approach seems fine. You could use the PDIST2 function and extract everything in one s...

1 year ago | 1

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Answered

python with matlab, undefined variable py?

Try going through: https://www.mathworks.com/help/matlab/matlab_external/undefined-variable-py-or-function-py-command.html and ...

python with matlab, undefined variable py?

Try going through: https://www.mathworks.com/help/matlab/matlab_external/undefined-variable-py-or-function-py-command.html and ...

2 years ago | 0

Answered

How to slice each string in a string array without using for loop

If you favor performance over readability/maintainability, you can build an approach around the following: buffer = vertcat(...

How to slice each string in a string array without using for loop

If you favor performance over readability/maintainability, you can build an approach around the following: buffer = vertcat(...

2 years ago | 4

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Answered

How to retrieve z value from surf plot given x and y?

Interpolate with |INTERP2| : <https://www.mathworks.com/help/matlab/ref/interp2.html> where |Xq| and |Yq| are defined using t...

How to retrieve z value from surf plot given x and y?

Interpolate with |INTERP2| : <https://www.mathworks.com/help/matlab/ref/interp2.html> where |Xq| and |Yq| are defined using t...

2 years ago | 0

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Answered

Writing a loop to calculate a seasonal cycle and then plot the seasonal cycle?

Where is |t| defined? In addition, |month_mean| is your intermediary variable; you want to plot either |seasonal_cycle| or |s_cy...

Writing a loop to calculate a seasonal cycle and then plot the seasonal cycle?

Where is |t| defined? In addition, |month_mean| is your intermediary variable; you want to plot either |seasonal_cycle| or |s_cy...

3 years ago | 0

Answered

How to read large text data into matlab

If you have enough RAM for this, the following could run a little faster. It is way less versatile than Per's solution though, a...

How to read large text data into matlab

If you have enough RAM for this, the following could run a little faster. It is way less versatile than Per's solution though, a...

3 years ago | 1

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Answered

How can I create a matrix with the values of the elements is a function of the indices?

Not sure that I understand. If you wanted to create a rectangular array whose elements are a the result of some arithmetic opera...

How can I create a matrix with the values of the elements is a function of the indices?

Not sure that I understand. If you wanted to create a rectangular array whose elements are a the result of some arithmetic opera...

3 years ago | 0

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Answered

Strfind to contain complex pattern

Here is an approach: str = 'John played volleyball. I love Anna. Are you there?' ; buffer = strtrim( strsplit( str, {'....

Strfind to contain complex pattern

Here is an approach: str = 'John played volleyball. I love Anna. Are you there?' ; buffer = strtrim( strsplit( str, {'....

3 years ago | 0

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Answered

Rearrange cell content by groups

Hi |dpb|, Assuming that you have a cell array (and that you are using this _table type of output_ just for a _display purpose...

Rearrange cell content by groups

Hi |dpb|, Assuming that you have a cell array (and that you are using this _table type of output_ just for a _display purpose...

3 years ago | 0

Question

Solving A{k} * x + b = 0 for large numbers of A{k} with same structure/filling.

Dear all, I am trying to improve the efficiency of solving |A{k}*x+b=0| for |x|, that I currently solve using the...

3 years ago | 2 answers | 0

Question

Should I (and how to) avoid "forests" of listeners in nested OOP structure.

Dear all, I never used more than the basics of events and listeners, and I could benefit from the input of ...

3 years ago | 0 answers | 0

Question

Dynamic superclass name in call to superclass method.

Dear all, In a particular context, I could benefit from being able to use _"dynamic superclass naming"_ in calls...

3 years ago | 0 answers | 2

Question

Error management in OOP framework.

Dear all, I am trying to implement an error management mechanism that allows building very detailed error r...

3 years ago | 1 answer | 1

Answered

How to vertcat 100 matrices ?

If they are stored in cell array |M|: Mvcat = vertcat( M{:} ) ; where |M{:}| is what we call a _comma separated list_ (CS...

How to vertcat 100 matrices ?

If they are stored in cell array |M|: Mvcat = vertcat( M{:} ) ; where |M{:}| is what we call a _comma separated list_ (CS...

3 years ago | 1

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Answered

print leading and trailing zeros into text file

>> dec2hex(195112160, 8) ans = '0BA12CE0'

print leading and trailing zeros into text file

>> dec2hex(195112160, 8) ans = '0BA12CE0'

3 years ago | 0

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Answered

Finding and saving identical rows in a matrix

Alternatively: [~, ~, ic] = unique( A(:,1:2), 'rows' ) ; groups = splitapply( @(x){x}, A, ic ) ; produces groups = ...

Finding and saving identical rows in a matrix

Alternatively: [~, ~, ic] = unique( A(:,1:2), 'rows' ) ; groups = splitapply( @(x){x}, A, ic ) ; produces groups = ...

3 years ago | 1

| accepted

Answered

How extract sub matrix without zeros from a big matrix

Here is an example; we first build a test data set: >> N = randi( 10, 10, 4 ) ; >> for k = 1 : 10, N(k,1+randi(3,1):end) =...

How extract sub matrix without zeros from a big matrix

Here is an example; we first build a test data set: >> N = randi( 10, 10, 4 ) ; >> for k = 1 : 10, N(k,1+randi(3,1):end) =...

3 years ago | 2

| accepted

Answered

How to remove repeating elments from a matrix?

Almost, the idea was correct but you were not working on the correct dimension. Also, sorting the input array vertically makes c...

How to remove repeating elments from a matrix?

Almost, the idea was correct but you were not working on the correct dimension. Also, sorting the input array vertically makes c...

3 years ago | 0

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Answered

sum of matrix omitting one dimension

Here is one way, but there is probably a simpler approach: buffer = arrayfun(@(k) permute(KL, circshift(1:ndims(KL), k-1)), ...

sum of matrix omitting one dimension

Here is one way, but there is probably a simpler approach: buffer = arrayfun(@(k) permute(KL, circshift(1:ndims(KL), k-1)), ...

3 years ago | 0

Answered

Split array into cell arrays of different size

>> seqs = mat2cell( A, 1, diff( [strfind(A, [5,19]), numel(A)+1] )) seqs = 1×5 cell array {1×4 double} {1×3 doub...

Split array into cell arrays of different size

>> seqs = mat2cell( A, 1, diff( [strfind(A, [5,19]), numel(A)+1] )) seqs = 1×5 cell array {1×4 double} {1×3 doub...

3 years ago | 0

Answered

Find if two sparse matrix have 1 in same position

Do you need something along this line? % - Build small test case. A = sprand( 4, 5, 0.5 ) > 0 ; % 4x5 sparse. B =...

Find if two sparse matrix have 1 in same position

Do you need something along this line? % - Build small test case. A = sprand( 4, 5, 0.5 ) > 0 ; % 4x5 sparse. B =...

3 years ago | 0

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Answered

How to import Text File with 2 different Delimiters (how to organize header data and numeric data)

You may not need to use header information for parsing your file. Look at this example (applied to |data.txt| attached): ...

How to import Text File with 2 different Delimiters (how to organize header data and numeric data)

You may not need to use header information for parsing your file. Look at this example (applied to |data.txt| attached): ...

3 years ago | 0