Why is unique() giving me the matrix after eliminating the common rows for these two matrices?

I have A =

0.0000 0.0000

0.0000 1.0000

0.0000 0.0000

0.0000 1.0000

1.0000 0.0000

1.0000 0.0000

1.0000 1.0000

B =

0.1000 0.1000

0.1000 0.9000

0.1000 0.1000

0.1000 0.9000

0.9000 0.1000

0.9000 0.1000

0.9000 0.9000

After using unique I am still getting the exact same matrix as my output. Can anyone tell me why is that?

[Jan]

Please post your code and the input data. Currently all we see is A and B and that you mention, that unqiue has been used anywhere.

Answer 1

[Jan]

If you use a matrix as input to unique, a vector is replied. So if you matrix is not changed, it cannot be an output of unique(). Because you did not post your code, I guess something like this happens:

B = [0.1000    0.1000
     0.1000    0.9000
     0.1000    0.1000
     0.1000    0.9000
     0.9000    0.1000
     0.9000    0.1000
     0.9000    0.9000];
unique(B);   % This is no effect!

% You need:
uB = unique(B)
% Or maybe:
uB = unique(B, 'rows')

[SL: fixed typo]

Answer 2

[Steven Lord]

If you're trying to find unique rows, two rows that display the same may not contain the same stored values.

A = [1 2; 1+eps 2] % First and second rows are NOT the same

A = 2×2

1.0000 2.0000 1.0000 2.0000

unique(A, 'rows')

ans = 2×2

1.0000 2.0000 1.0000 2.0000

To allow "close enough" to count you'd want to use uniquetol.

uniquetol(A, eps, 'ByRows', true)

ans = 1×2

1 2