matlab cell array, count number of different elements - matlab

Question

I have 2 cell arrays as below:
A = {'S' 'M' 'N' 'E'};
B = {'E' 'M' 'Q' 'S'};
In this case, the number of different elements is 3.
In a number array, I can use length(find(A ~= B)); to easily count number of different elements in one step easily.
Is there something similar for cell array of characters?

Answer 1

EDIT: I think I've misunderstood your question, and you probably meant finding different elements in corresponding positions in the arrays. I still kept my old answer
Counting different elements at the same position
yuk's approach with strcmp is correct. However, it works only if the two arrays are of the same size. The generalized solution would be:
N = min(numel(A), numel(B));
sum(~strcmp(A(1:N), B(1:N))) + numel(A) + numel(B) - 2 * N
If the arrays are of different length, the "extra" elements in the larger array will be counted as different here.
Counting different elements in any position
The most general approach would be using ismember, which does not care about lengths of strings or their position in the array. To count the total number of elements in A and B that are different, just do:
sum(ismember(A, B)) + sum(ismember(B, A))
The same effect can also be obtained with setdiff (instead of ismember):
numel(setdiff(A, B)) + numel(setdiff(B, A))
Both ways are valid for any two arrays, not necessarily of equal size.

Answer 2

Try
cell2mat(A)==cell2mat(B)
to start with, the rest should be straightforward. This simple approach will fail if the cell arrays don't have the same dimensions.

Answer 3

If your cell array is a cell array of strings you can use STRCMP:
sum(~strcmp(A,B))
Of course make sure A and B have the same length.
By the way for numeric array it's more efficient to use sum(A~=B). In general find is slow.

Answer 4

U can also try unique([A B]) if A and B are given in the exemple you gave.
It A and B do not have the same dimension you can try this.
unique(reshape(cell2mat(A,1,[])),reshape(cell2mat(B,1,[])))