MATLAB: Behavior of “unique” with mixed complex numbers

Question

I have a large set of complex number that I want to map to an integer grid on the complex plane, removing redundant values. A small subset of the data looks like:

Atest=[-12.9753 - 0.8003i;
     -12.9938 - 0.4003i;
     -13.0000 + 0.0000i;
     -12.9938 + 0.4003i;
      12.9938 + 0.4003i;
      13.0000 + 0.0000i;
      12.9938 - 0.4003i;];

I use round to map to the grid:

Around=round(Atest)
Around =
 -13.0000 - 1.0000i
 -13.0000 + 0.0000i
 -13.0000 + 0.0000i
 -13.0000 + 0.0000i
  13.0000 + 0.0000i
  13.0000 + 0.0000i
  13.0000 + 0.0000i

I then use unique to remove the redundant values:

  Aunique=unique(Around,'stable')
Aunique =
 -13.0000 - 1.0000i
 -13.0000 + 0.0000i
 -13.0000 + 0.0000i
  13.0000 + 0.0000i

Clearly, the result is not unique: the value -13 appears twice. If I apply unique to just the las 6 values of Around (the real values) I obtain the expected results:

  Aunique=unique(Around(2:end),'stable')
Aunique =
   -13
    13

I would appreciate any suggestions for getting the unique values of an array with mixed real and complex values.

Answer 1

Please let me know if I understood correctly your qestion

    Atest=[-12.9753 - 0.8003i;
         -12.9938 - 0.4003i;
         -13.0000 + 0.0000i;
         -12.9938 + 0.4003i;
          12.9938 + 0.4003i;
          13.0000 + 0.0000i;
          12.9938 - 0.4003i;];
      
      Around=round(Atest);
      A=[real(Around) imag(Around)];
      unique(A,'rows')

ans =

-13 -1

-13 0

13 0