how to xor binary vector in matrix

hello.. i have

Answer 1

[Roger Stafford]

If I understand what you want and if the rows have a multiple of three elements, this should work for you:

 X = xor(xor(M(:,1:3:end-2),M(:,2:3:end-1)),M(:,3:3:end));

If this is not what you want, you should clarify that phrase "every three bits together" so that it is clearly understood. As it stands, it is easily misunderstood. It should be simple to make it clear what you mean if you carefully construct a good, meaningful example.

[jim]

thanks roger.. it works , but for 32 bit file it doesn't work right until i add zero to the last left bit. so i need this code to add zero automatically if the number of bits is not a multiple of three elements,how to make the code do this automatically ?

[Roger Stafford]

How about this:

   [m,n] = size(M);
   M2 = [M,zeros(m,3*ceil(n/3)-n)];
   X = xor(xor(M2(:,1:3:end-2),M2(:,2:3:end-1)),M2(:,3:3:end));

[Roger Stafford]

When you used the word 'last' I thought you wanted the extra zeros appended to the right end. Apparently you want them appended to the left end. If that is the case, just reverse the order:

   [m,n] = size(M);
   M2 = [zeros(m,3*ceil(n/3)-n),M];
   X = xor(xor(M2(:,1:3:end-2),M2(:,2:3:end-1)),M2(:,3:3:end));

[jim]

thank you very much,, it works fine