Finding Rows where a condition is satisfied

I have a 2 column matrix (A) consisting of id numbers in each column to a length of around 5000

I have two smaller column vectors (B & C) which lists a smaller section of id's.

In the first case I want to find rows in A which include an id found in B.

In the second case I want to find rows in A which contain an id found in B & C, or C & B (column order doesn't matter).

I have attempted this by:

[ia ib] = ismember(A(:,1), B);

But this checks only if B is in the first column, ignoring entries where it may be in the second. I would like the rows where one column contains an id from B to then added to a new matrix, D.

I'm looking at doing the same if a row has an id from B and C (not just one column, either column in either order) and adding this information to new matrix E.

Kind Regards,

Dwayne

[Walter Roberson]

This is not correct.

>> [ia, ib ] = ismember(4, [1 2; 3 4])

ia =

  logical

   1


ib =

     4

4 only occurs in the second column of B, but it was found.

When you use ismember() without the 'rows' option, then the second argument is treated as-if you had used (:) with it, like ismember(A(:,1), B(:))

If you are not getting a match then it is for some other reason.