# Cedric Wannaz

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

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**Content Feed**

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...

plus d'un an ago | 0

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)

plus d'un an ago | 0

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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'...

plus d'un an ago | 0

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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 ...

plus d'un an ago | 0

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.

plus d'un an ago | 0

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...

plus de 2 ans ago | 1

| accepted

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...

plus de 2 ans ago | 2

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...

plus de 2 ans ago | 0

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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...

plus de 2 ans ago | 1

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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 ...

plus de 2 ans ago | 0

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(...

environ 3 ans ago | 4

| accepted

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...

environ 3 ans ago | 0

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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...

presque 4 ans ago | 0

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...

presque 4 ans ago | 1

| accepted

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...

presque 4 ans ago | 0

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Strfind to contain complex pattern

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

presque 4 ans ago | 0

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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...

presque 4 ans 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...

presque 4 ans ago | 2 answers | 0

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answersQuestion

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 ...

presque 4 ans ago | 0 answers | 0

### 0

answersQuestion

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...

presque 4 ans ago | 0 answers | 2

### 0

answersQuestion

Error management in OOP framework.

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

environ 4 ans ago | 1 answer | 1

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answerHow 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...

environ 4 ans ago | 1

| accepted

print leading and trailing zeros into text file

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

environ 4 ans ago | 0

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Finding and saving identical rows in a matrix

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

environ 4 ans ago | 1

| accepted

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) =...

environ 4 ans ago | 2

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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...

environ 4 ans ago | 0

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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)), ...

environ 4 ans ago | 0

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...

environ 4 ans ago | 0

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 =...

environ 4 ans ago | 0

| accepted

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): ...

environ 4 ans ago | 0