How to check if a column data is equal to any of a group of values?

I have a column data A like the below:

A = [1; 3; 2; 7; 11; 6];

B can be a group of numbers with unknow counts. For example B can be like the below:

B = [1; 7];

Here is my question. How do I come up with an index to show the elemens of A that can be any of B? For example if I know B has two elements, I can use something like the below, but B can have an unknown number of elements.

Ind1 = A == B(1);
Ind2 = A == B(2);
Ind = Ind1 + Ind2;

Answer 1

[Sulaymon Eshkabilov]

Hi,

Ind = sum(Ind1) + (Ind2);

[Leon]

Thanks!

Is there a better way to do this? B has an unknown number of elements, not necessarily 2.

Answer 2

[Sulaymon Eshkabilov]

You can use a loop for instance if you have many Bs, e.g.:

 for ii = 1:numel(B)
     Ind = A==B(ii); S(ii) = sum(Ind(:)); 
 end
 S_all=sum(S);   % Total number of observed cases

[Leon]

Thank you. Unfortunately, it did not work. Were you trying to ask me to do something like this?

for i=1:numel(B)
    Ind(:,i) = A==B(i);
end
S = sum(Ind,2);

The problem is that after we sum the logical valeus, I get this error. It seems the function sum messed it up.

Array indices must be positve integers or logical values.

Anyone knows how to find the indices without writing a loop? Many thanks.

[Sulaymon Eshkabilov]

You have edited the code that I've provide incorrectly.

Answer 3

[Sulaymon Eshkabilov]

Altenrative (more efficient one) solution can be this one:

S = sum(sum(ismember(A,B)))   

Answer 4

[madhan ravi]

clear sum
Ind = sum(ismember(A, B), 2)
%Or perhaps you need
Ind = nnz(ismember(A, B))
%or
fprintf('%d occurs %d times/s\n', [B.'; sum(A == B.')])