Arranging the cell array in the corresponding rows.

I have a cell array which has the following format: action (a1,a2,a3,...) and followed by the corresponding "id-number" like(01,02,03,.....) i want to generate an output in which all the unique "id-number" belongs to one group.

if true
  c_in = {'a1ev01','a1ev02','a2ev01','a2ev02','a3ev01','a3ev02'}; % and so on....

    % output
    c_out = {'a1ev01','a2ev01','a3ev01';...
             'a1ev02','a2ev02','a3ev02';}; % or in another format of the same form
  end

[Cedric]

Is there the same number of elements for each group/ID?

Answer 1

[Andrei Bobrov]

c_in = {'a1ev01','a1ev02','a2ev01','a2ev02','a3ev01','a3ev02'};

ii = regexp(c_in,'\d*','match');
i1 = str2double(cat(1,ii{:}));
c_out = accumarray([i1(:,2),i1(:,1)],(1:numel(c_in))',[],@(x)c_in(x));

[pr]

@Andrei Bobrov thanks for the help. Excellent solution

Answer 2

[the cyclist]

Related to Cedric's question in his comment ... Is it a simple reshape?

c_out = reshape(c_in,2,[])

[pr]

it works only in the case for "2" "id-numbers" fails in the case when ther is a 3rd "id-number" or 4th and so on.

if true
  c_in = {'a1ev01','a1ev03','a2ev01','a2ev02','a3ev03','a3ev02'}; 
end

[Cedric]

If there is always the same number of elements per group/ID and the order follows always the same schema, you (pr) can perform a reshape based on an appropriate number of rows or columns. If the second condition falls, there is a little more work but you can still store the outcome in a rectangular cell array. If both conditions fail, you must build a cell array of cell arrays.