How to find common rows between two cell arrays containing string values?

I have two cell arrays A and B containing string values of the form like this :

A = (ABC , DEF ;

HTG , JUKHI;

RTHG,KIO)

B = (HTG , JUKHI;

GHTY , UJIK;

RTGHY, IOP)

I want to find the common rows from these cell arrays, i.e., output = [HTG , JUKHI]

How to do that? I have tried ismember, but it doesnot give correct ans because I want to match exact rows and not just one entry in a row. Any solutions?

[Jan]

This is no valid Matlab code to create "string values". Therefore the readers have to guess, what your inputs are. So please post some code, which creates the inputs.

Answer 1

[Jan]

What about ismember(A, B, 'rows')?

I guess your inputs are:

A = ["ABC",  "DEF"; ...
     "HTG",  "JUKHI"; ...
     "RTHG", "KIO"];
B = ["HTG",   "JUKHI"; ...
     "GHTY",  "UJIK"; ...
     "RTGHY", "IOP"]
index  = ismember(A, B, 'rows');
result = A(index, :)

or:

result = intersect(A, B, 'rows')

[Deepika Vatsa]

'rows' argument does not go with cell arrays in ismember

[Jan]

@Deepika Vatsa: You did not mention, that you are talking of cell string. I asked you in a comment, what your inputs are and you did not reply to my comment. It wastes time to let the readers guess, what your inputs are.

The code I have posted works as expected. So simply use strings instead of cell strings.

A = {'ABC',  'DEF'; ...
     'HTG',  'JUKHI'; ...
     'RTHG', 'KIO'};
B = {'HTG',   'JUKHI'; ...
     'GHTY',  'UJIK'; ...
     'RTGHY', 'IOP'};
[~, iA] = intersect(strcat(A(:,1), '*', A(:,2)), ...
                    strcat(B(:,1), '*', B(:,2)));
Result = A(iA, :);

Answer 2

[Alex Mcaulley]

An option:

A = {'ABC','DEF';'HTG','JUKI';'RTHG','KIO'};
B = {'HTG','JUKI';'GHTY','UJIK';'RTGHY','IOP'};
setdiff(A,setdiff(A,B))

[Alex Mcaulley]

Or:

A = {'ABC','DEF';'HTG','JUKI';'RTHG','KIO'};
B = {'HTG','JUKI';'GHTY','UJIK';'RTGHY','IOP'};
intersect(A,B)

[Deepika Vatsa]

setdiff also does not take each row as a single entity as required in this problem

[Alex Mcaulley]

Ohhh sorry I haven't understood. I think this is a robust solution:

A = {'ABC','DEF';'HTG','JUKI';'RTHG','KIO'};
B = {'HTG','JUKI';'GHTY','UJIK';'RTGHY','IOP'};
try
    res = A(ismember(strcat(A(:,1),A(:,2)),intersect(strcat(A(:,1),A(:,2)),strcat(B(:,1),B(:,2)))),:);
catch
    res = [];
end

[Deepika Vatsa]

yeah this works! Thanks. BTW I got my solution using ismember function and using indexes like this:

[~ , idd1] = ismember(A(:,1),B(:,1));

[~ , idd2] = ismember(A(:,2),B(:,2));

idx = idd1 == idd2 & idd1 > 0 & idd2 > 0;

common_rows = A(idx,:);

Logical indexes just gives confusing answer. But your solution also works.

[Alex Mcaulley]

But your code doesn't work in your first example:

[~ , idd1] = ismember(A(:,1),B(:,1));
[~ , idd2] = ismember(A(:,2),B(:,2));
idx = idd1 == idd2;
common_rows = A(idx,:);
common_rows =

  3×2 cell array

    'ABC'     'DEF' 
    'HTG'     'JUKI'
    'RTHG'    'KIO' 

[Deepika Vatsa]

Yeah just figured out that. Edited my answer above.