Transposing the output of writecell

Each element of my cell array consists of a vector of a different length. I want to write these vectors to a file. I do this by:

writecell(C,'C_data.csv')

That does the trick, except the output file has row vectors. I want column vectors, so I tried transposing the cell array:

writecell(C','C_data.csv')

That results in one long row in the output file. I also tried transposing the elements inside the array:

C = cellfun(@transpose,C,'UniformOutput',false);
writecell(C,'C_data.csv')

That doesn't seem to do anything. How do I output my content as column vectors of different length?

[Benjamin Thompson]

The difficulty is the cell contents having different lengths, which means at the end of the CSV file you will have data in some columns missing. How are you going to represent that in CSV. Can you post some sample input/output examples for what you are trying to do? Note that you can save and reload this data in the binary MAT file format easily.

Answer 1

[Voss]

You can make a 2D cell array of size n_max-by-n_vectors, where n_vectors is the number of vectors in C and n_max is the length of the longest vector in C. Then fill it in from the top column-by-column with the contents of each vector in C:

C = {1 [1 2 3 4 5] [1 2 3]};

n = cellfun(@numel,C);
n_max = max(n);

n_vectors = numel(C);

C_aug = cell(n_max,n_vectors);
for ii = 1:n_vectors
    C_aug(1:n(ii),ii) = num2cell(C{ii}(:));
end

writecell(C_aug,'C_data.csv');

show_csv_contents('C_data.csv');

1,1,1
,2,2
,3,3
,4,
,5,

function show_csv_contents(fn)
fid = fopen(fn);
data = char(fread(fid).');
fclose(fid);
disp(data);
end

[L'O.G.]

Thank you!

[Voss]

Did that answer work for what you wanted to do? If so, please mark the answer as 'Accepted'. Thanks!

[L'O.G.]

Yes, thank you. Done. :)