cell2mat conversion in MATLAB (For ismember)

Question

I need to convert a column in 2 matrices to the same datatype so that I can run ismember. One column is in matrix [] format and the other is in string format i.e. we need to match [2000] with '2000'. Please see:

    mat1 = {'aa' [2001] ; 'ex' [10] ; 'ex' [1001]  ; 'rt' [4001] ;} ;
    mat2 = {'abc' '10' ; 'def' '4001' ; 'ghi' '2001' ; } ;

ismember(cell2mat(mat1(:,2)), cell2mat(mat2(:,2))) % Gives ERROR

%cell2mat(mat1(:,2) works just fine
%cell2mat(mat2(:,2)) is the PROBLEM.  

%Final answer
    ans = {...
     'aa' [2001] 'ghi'; 'ex' [10] 'abc'; 'ex' [1001] 'abc'; 'rt' [4001] 'def';} ;

Shall appreciate a vectorized code, if possible.

Answer 1

If you know that all of the second column of mat2 is going to be strings, you could convert them to numbers like so:

mat2(:,2) = cellfun(@str2num, mat2(:,2), 'UniformOutput', false)

Iterating through would also work, particularly if you're not sure they're all strings:

for i=1:size(mat2,1)
    if ischar(mat2{i,2})
        mat2{i,2} = str2num(mat2{i,2});
    end
end

Answer 2

From what I understand, you want to merge the rows from the two sets based on the second column. Here is my implementation:

%# data
mat1 = {'aa' [2001] ; 'ex' [10] ; 'ex' [1001]  ; 'rt' [4001] ;} ;
mat2 = {'abc' '10' ; 'def' '4001' ; 'ghi' '2001' ; } ;

%# sorted row keys
[key1 ord1] = sort( cell2mat(mat1(:,2)) );
[key2 ord2] = sort( str2double(mat2(:,2)) );

%# match rows based on key
[idx1 loc1] = ismember(key1,key2);
[idx2 loc2] = ismember(key2,key1);

%# merge
merged = [mat1(ord1(loc2(idx2)),:) mat2(ord2(loc1(idx1)),1)];

The result:

>> merged
merged = 
    'ex'    [  10]    'abc'
    'aa'    [2001]    'ghi'
    'rt'    [4001]    'def'