Union of two matrices with different column size

I need to make the union between two matrices:

M 455799x3
N 771719x3

I attach the workspace with the two matrices inside. What I have to do is to insert the values that are in the 3rd column of M in the 3rd column of N. The first 2 columns of both the matrix represent X coord and Y coord but the problem is that the coordinates of the matrices are not in the same order.

Answer 1

[Stephen23]

>> [idm,idn] = ismember(M(:,1:2),N(:,1:2),'rows');
>> N(idn,3) = M(idm,3);

Note that the provided data are floating point, so you should definitely read this:

http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F