Use of CELLFUN instead of FOR loop

I have a 21x40 cell array with each cell containing a vector of variable length. I want to merge all of the cells in each column. I can achieve this using a FOR loop such as

A = 21x40 cell array
for n = 1:40
merge = cat(2,A{:,n})
end

How can I do this with, for example, CELLFUN or in some other way without using a FOR loop? Thanks a lot for any help.

Answer 1

[Azzi Abdelmalek]

A=num2cell(rand(21,40)) % Example
out=arrayfun(@(x) cat(2,A{:,x}),1:size(A,2),'un',0)

[Neil]

Thanks! I tried something similar with cellfun but that didn't work.

[Jan]

This is a fast and short method. The "merge{n}= cat(2,A{:,n})" approach inside a loop is 50% faster.

Answer 2

[Azzi Abdelmalek]

for n = 1:40
merge = cat(2,A{:,n})
end

is the same then

merge = cat(2,A{:,40})

[Neil]

This solution merges all the rows only of column 40 into a single vector. What I want to do is merge each column of cells such that you end up with a 1x40 cell array where each cell contains a merged vector of the cell rows.

[Azzi Abdelmalek]

That's what your code, also do

[Neil]

The for loop in my code does this on a per column basis. As I understand your code it only works on a single column. Am I missing something about your code?

[Azzi Abdelmalek]

Your for loop should be: (merge{n} instead of merge)

for n = 1:40
merge{n}= cat(2,A{:,n})
end