concatenate cell array of cell arrays

I have got this cell variable with 10 cell arrays. It is possible to horizontally concatenate them if the dimension is consistent but if not it gives me an error. How do i concatenate this cell arrays of unequal length?

Answer 1

[Stephen23]

Where C is your cell array, all of these are equivalent:

[C{:}]
horzcat(C{:})
cat(2,C{:})

https://www.mathworks.com/help/matlab/matlab_prog/comma-separated-lists.html

https://www.mathworks.com/matlabcentral/answers/1656435-tutorial-comma-separated-lists-and-how-to-use-them

[Ghenji]

Error using horzcat Dimensions of matrices being concatenated are not consistent.

I have tried this all variations nothing works. Thing is dimensions are inconsistent.

[Stephen23]

Note that you could vertically concatenate them without any problem, as they all have exactly one column.

If you really need to horizontally concatenate them you will need to pad their rows first so that they have the same number of rows: you could use a loop, or cellfun. Or just do something like this:

col = size(C,2);
row = cellfun('size',C,1);
out = cell(max(row),col);
for k = 1:col
    out(1:row(k),k) = C{k};
end

[Ghenji]

well well!! That worked. Thanks a lot Stephen.

Answer 2

[Rishabh Rathore]

I'm assuming you want to retain the data of one cell array as a column.

A work around could be the following

• Find the length of the longest cell array
• append the empty cell to all the smaller cell arrays
• finally concatenate them, you may use horzcat for horizontal concatenation.