Matlab, Find cell elements

Question

I have two cell arrays of string A and B. All cells of B are also in A. I want to find the index of cell of B in A. Thanks.

Example:

A=
 'aaaa'
 'bbbb'
 'cccc'
 'dddd'
 'ffff'

B=
 'ffff'
 'aaaa'

ans=
  5
  1

or

ans=
  1
  5

Answer 1

use either intersect or ismember

[~, idxInA] = intersect(A,B)

or

LocInA = find(ismember(A,B))

Answer 2

You can do this really simply, use the code below

indices = cell(size(B));
for i = 1:numel(B)
    indices{i} = find(strcmpi(A,B(i)));
end

While I do recommend using ismember or intersect , those solutions will not handle case insensitive solutions. Also, those methods will not indicate how many times a specific index was matched, where my solution, will return all indices that match for each comparison.

UPDATE

Code I am running to test this.

A={'aaaa','bbbb','cccc','dddd','ffff','aaaa'};
B={'ffff','aaaa','cccc','qwerty'};
indices = cell(size(B));
for i = 1:numel(B)
    indices{i} = find(strcmpi(A,B(i)));
end
indices

Which returns the following

indices = 

    [5]    [1x2 double]    [3]    [1x0 double]

I do not see where you are having problems