How do I combine two cell arrays into one cell array?

 >> Q{1}
 ans = 
    '4400002970000003533'
    '4400002970000003533'
    '4400002970000003535'
    '4400002970000003536'
    '4400002970000003533'
    '4400002970000003532'
    '4400002970000003537'

 >> Q{2}
 ans = 
    '4400002890000146180'
    '4400002890000146180'
    '4400002970000000026'

I want to get a new cell:

    '4400002970000003533'
    '4400002970000003533'
    '4400002970000003535'
    '4400002970000003536'
    '4400002970000003533'
    '4400002970000003532'
    '4400002970000003537'
    '4400002890000146180'
    '4400002890000146180'
    '4400002970000000026'

I don't want to use the function cell2mat, because it is too slow for my program. Do you have any good ideas?

Answer 1

[Star Strider]

To get the result cell array ‘R’, for instance, vertically concatanate ‘Q{1}’ and ‘Q{2}’:

Q{1} = ['4400002970000003533'
    '4400002970000003533'
    '4400002970000003535'
    '4400002970000003536'
    '4400002970000003533'
    '4400002970000003532'
    '4400002970000003537'];

Q{2} = ['4400002890000146180'
    '4400002890000146180'
    '4400002970000000026'];

R = {[Q{1}; Q{2}]};

celldisp(R)         % Display Result

[pengcheng]

If i want to combine them from Q{1}to Q{100},i should use a loop ?or you have some good idea,thank you very much

[Iain]

You could try: {[Q{:}]}

[pengcheng]

I try to use this,but i doesn't work ,Error using horzcat Dimensions of matrices being concatenated are not consistent.

[Star Strider]

Thank you Iain!

Simply doing:

R = Q{:};

also works.

[Adam]

R = vertcat(Q{:})

seems to work.

[Star Strider]

@pengcheng — It is a vertical condatanation, not a horizontal concatanation. The semicolon ; between ‘Q{1}’ and ‘Q{2}’ in my original code is important. It puts ‘Q{1}’ on top of ‘Q{2}’, not beside it, equivalent to:

R = {[Q{1}
    Q{2}]};

[Adam]

I assume he is referring to the more generic answer of {[Q{:}]} which does horizontal concatenation by default.

It is one of the many cases where someone asks a question using a neat example then when given a correct answer for that it turns out they actually want to solve the general case that wasn't mentioned in the example!!

[Star Strider]

@Adam — The vertcat function is definitely the way to go!

You’re certainly correct on your observation — in more Questions that I care to count, the instance in the question may have little bearing on actual issue!

Answer 2

[Chenchal]

cell2mat(Q')

Answer 3

[Josep Llobet]

Maybe this little function could be useful:

function [celltot] = juntar_cells(cell1, cell2)

celltot = cell1;
for ll_cell2 = 1:length(cell2)
    celltot{end + 1} = cell2{ll_cell2};
end

end