comparing 2 vectors for duplicates

Hello,

I have a vector of 465051 x 1 elements, and a vector of 1197 x 1 elements. The 465051 vector contains all the 1197 elements, but I don't know where. So I created the following code:

[num,txt,raw] = xlsread('cg_uit_beta2'); %extracting the 465051 vector
A = txt(:,1); %extracting the 465051 vector
[num2,txt2,raw2] = xlsread('cg_uit_beta2_2'); %extracting the 1197 vector
B = txt2(:,1); %extracting the 1197 vector
L = ismember(A,B); %find rownumber of duplicates in the 465051 vector
I = find(L); %find rownumber of duplicates in the 465051 vector

So, now I know where the 1197 duplicates in the 465051 vector are. But now I just need to extract these values out of the 465051 vector... but how do I do that?

Thanks!

Answer 1

[Adam]

[L,I] = ismember(A,B);
vals = A(I~=0);

should work. The extra 'find' step is un-necessary if you use the second output of ismember. If you prefer though:

L = ismember(A,B);
I = find(L);
vals = A(I);