Substitute for join/ outerjoin in cell array?

It seems join and outerjoin only work for tables. Is there a substitute for cell arrays?

Answer 1

[Guillaume]

Well, you can always convert your cell arrays to a table with cell2table, do the join and convert back.

Otherwise, it's not particularly hard to implement using ismember:

%INPUTS:
%leftcell: first cell array
%rightcell: second cell array
%leftkeys: column indices for left key
%rightkeys: column indices for right key

%JOIN:
[common, rows] = ismember(leftcell(:, leftkeys), righcell(:, rightkeys), 'rows');
joinedcell = [leftcell(common, :), rightcell(rows, :)];

%OUTERJOIN:
[commonleft, rows] = ismember(leftcell(:, leftkeys), righcell(:, rightkeys), 'rows');
commonright = ismember(rightcell(:, leftkeys), leftcell(:, rightkeys), 'rows');
joinedcell = [leftcell(commonleft, :), rightcell(rows, :)];
joinedcell = [joinedcell;                    ... normal join
              [cell(sum(~commonright), size(leftcell, 2)), rightcell(~commonright, :)]; ... add non matching rows from rightcell
              [leftcell(~commonleft, :), cell(sum(~commonleft), size(righcell, 2))]];  ...add non matching rows from leftcell

I've not merged the left and right keys. It's not particularlty hard to do, and you could also select which columns to include in the join, but you should get the idea from the above.

Answer 2

[KSSV]

You can join them...

   k{1} = 1 ;
   k{2} = [2 3] ;

   l{1} = [3,4];
   l{2} = [5] ;
% join them 
   kl = [k l] ;

[phlie]

Thank you. Am I missing something or is there no merging key in your answer? Join/ outerjoin allows me to join data based on a common value of data k and l, i.e., I can merge even if the data is not ordered the same way (or if the dimensions don't match).

[Guillaume]

@Siva,

The joins ( join, innerjoin, outerjoin) in question are special functions that are not simple concatenation.

The concept comes from relational databases.