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# Stephen Cobeldick

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6.600 total contributions since 2014

Suspensa Vix Via Fit

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How to sum the second poation data in an array (50000x2) with the same value in the first position
Method one: accumarray: >> [U,~,G] = uniquetol(A(:,1)); >> S = accumarray(G(:),A(:,2)); >> M = [U,S] M = 2.79314 0.141...

etwa 4 Stunden ago | 0

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read csv. convert char-array to matrix
Because MATLAB does not handle UCS-2 file I first converted your file to UTF-8 (attached). This imports all of the main matrix ...

etwa 7 Stunden ago | 0

Help with printing output
Instead of adding spaces manually you can set the fieldwidth: hours = [13,22,41]; x = [74.52,30.02,22.68]; y = [77.40,36.30,2...

ein Tag ago | 0

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Access all k-th elements of a n-dimensional array, where the k indexes are defined in a (n-1)-dimensional array.
>> S = size(A); >> [R,C,~] = ndgrid(1:S(1),1:S(2),1); >> X = sub2ind(S,R,C,idx); >> B = A(X) B = 1 11 3 13 ...

ein Tag ago | 0

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For loop using bin2dec conversion
This is MATLAB, you don't need a for loop! Method one: mtimes: >> V = [1,1,0,1,0,0,1,0]; >> N = 2; >> X = pow2(N-1:-1:0)*res...

4 Tage ago | 0

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Matrix Generation from Other Matrices
F = @(p)C*A^p*B; M = arrayfun(F,0:n-1,'uni',0); M = cumsum(cat(3,M{:}),3); M = reshape(permute(M,[1,3,2]),[],b); Tested: >>...

4 Tage ago | 0

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Replacing NaN's in column of a Matrix
Where M is your matrix: X = isnan(M(:,2)); M(X,2) = 250;

5 Tage ago | 1

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For loop goes longer than expected.
"Can you help me what is the cause for this behaviour?" Because that is the indexing that you used. You defined the loop itera...

5 Tage ago | 0

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Average of the nine surrounding cells
Use conv2 to calculate the averages, e.g.: out = matrix2.*conv2(matrix1,ones(3,3),'same')/9;

5 Tage ago | 1

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How to separate an array into 3
>> A = [11,22,33,44,55,66,77,88,99]; >> B = A(1:2:end-1) B = 11 33 55 77 >> C = A(2:2:end-1) C = 22 44 66 88...

5 Tage ago | 1

modify the matrix, rearrangement of elements
>> a = [2,4,7,11;7,9,5,54;2,5,7,9;12,41,45,21] a = 2 4 7 11 7 9 5 54 2 5 7 ...

7 Tage ago | 1

How can I create a new cell array from an existing one?
Country = strrep(Country,'"','')

7 Tage ago | 0

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Numerical error representing data in Format Long
"I have had a surprise making with this simple multiplication:" Nothing in that result is surprising. "The result must be 8.2e...

7 Tage ago | 1

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Is it possible to determine within a function the location of that function?
https://www.mathworks.com/help/matlab/ref/mfilename.html p = mfilename('fullpath') [p,n] = fileparts(p)

7 Tage ago | 0

How to list files in the directory
https://www.mathworks.com/help/matlab/ref/dir.html D = 'absolute/relative path to where the files are saved'; S = dir(fullfile...

8 Tage ago | 0

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Concatenate same fields in multiple structures in a loop using field names
Because all of the structures contain the same fieldnames they should be stored as one non-scalar structure: https://www.mathwo...

8 Tage ago | 0

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How to generate all combinations of N struct vectors.
It is much simpler when those structures are stored in one cell array, e.g.: C{1}(1).a = 5; C{1}(2).a = 9; C{2}(1).b = 2; C{...

8 Tage ago | 0

Call to function with multiple outputs
[~,y2] = f(x) https://www.mathworks.com/help/matlab/matlab_prog/ignore-function-outputs.html

8 Tage ago | 0

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Saving previous values in a function to use them within it
https://www.mathworks.com/help/matlab/ref/persistent.html

8 Tage ago | 0

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Sort Data by Second Column
Use sortrows, e.g. where M is your matrix: M = sortrows(M,2); If you really want to use sort, then of course you will need to ...

9 Tage ago | 0

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how to plot a vector
"what's wrong with my code?" you preallocate a variable named Vho which you never use again. inside the loop you allocate to a...

10 Tage ago | 1

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Error : Undefined variable
You incorrectly transcribed the error message: the actual character shown is lower-case L, i.e. l, not a 1 like you showed. To a...

10 Tage ago | 0

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Suppressing ans in a function
To avoid the ans you must use a semi-colon when you call the function: str = encrypt(...); % ^ you need this s...

11 Tage ago | 0

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I keep getting two answers for my code
fconvg = int(k*j, x, 0, t) % ^ missing semi-colon This line should probably come after the if-end. Th...

12 Tage ago | 0

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Solving linear system 2 equations, 2 unknowns, not A = b*C form
Using a numeric solver or the symbolic toolbox is like using a sledge-hammer to crack open a tiny walnut! It is very simple to ...

12 Tage ago | 0

Button Colors and Shapes in GUIDE
http://undocumentedmatlab.com/articles/modifying-matlab-look-and-feel https://www.mathworks.com/matlabcentral/fileexchange/4086...

12 Tage ago | 0

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How to find the index of first and last nonzero elements in each column?
This works for any array, 2D, 3D, etc., and returns the requested linear indices: >> A = [0,0,0,0;0,0,0,0;1,0,4,8;2,0,5,9;3,1,6...

12 Tage ago | 1

Create one file from many files
D = 'absolute/relative path to where the files are saved'; N = 25; % number of files C = cell(1,N); for k = 1:N F = full...

12 Tage ago | 0