Finding equal rows in a matrix

I have a problem with finding equal elements in array. I searched and read all post about it, but i couldn't solve my problem. I have a 20x2 double array, t=0 and n=20. I want to find equal elements and result their row number. But i didn't. My code is at below :

   for i=1:n
     for j=2:n
         if neigbor(i,:,t)==neigbor(j,:,t)
             g(i,:)=i;
         else
             g(i,:)=0;
         end
     end
  end

I also tried unique and ismember functions. Like this:

[x,y,z] = unique(neigbor,'rows');

Not further. My neigbor(i,:,t) is at below, in this sample i want to see 8,9 and 10 row numbers.

neigbor =

       -4.2500   -3.5000
       -3.5000   -2.7500
       -2.7500   -2.0000
       -2.0000   -1.2500
       -1.2500   -0.5000
       -0.5000    0.2500
        0.2500    1.0000
        1.0000    1.7500
        1.0000    1.7500
        1.0000    1.7500
        1.7500    2.5000
        2.5000    3.2500
        3.2500    4.0000
        4.0000    4.7500
        4.7500    5.5000
        5.5000    6.2500
        6.2500    7.0000
        7.0000    7.7500
        7.7500    8.5000
        8.5000    9.2500

Where is my mistake? Can you make a suggestion or give any hint? If I repeat this question, sorry for that.

Answer 1

[Image Analyst]

This works. It could be made more compact but I wanted you to see each step of the way.

neigbor =[...
  -4.2500   -3.5000
  -3.5000   -2.7500
  -2.7500   -2.0000
  -2.0000   -1.2500
  -1.2500   -0.5000
  -0.5000    0.2500
  0.2500    1.0000
  1.0000    1.7500
  1.0000    1.7500
  1.0000    1.7500
  1.7500    2.5000
  2.5000    3.2500
  3.2500    4.0000
  4.0000    4.7500
  4.7500    5.5000
  5.5000    6.2500
  6.2500    7.0000
  7.0000    7.7500
  7.7500    8.5000
  8.5000    9.2500]
differencesFromRowAbove = diff(neigbor)
allZeroRows = all(differencesFromRowAbove == 0, 2)
rowsToKeep = find(allZeroRows)
% Add on first one
rowsToKeep = [rowsToKeep(1); rowsToKeep+1]

[Ozge Moral]

Understood what i was missing. It can be written as shortly,

z = find(all(diff(neigbor)==0,2)

Thank you a lot for writing step by step, it is useful.