Find unique in matrix of x,y coordinates

Hello, I would love your help.

If I have a matrix of x,y coordinates for example:

    x     y
A=[ 2.5  3.5
    1.2  3.5
    2.2  1.2
    1.2  3.5
    4.0  2.2 ]

How do I find a unique of this? In the above example one instance of x,y (1.2, 3.5) will be removed?

Answer 1

[Kelly Kearney]

To find unique rows, you can use unique with the 'rows' option. (The 'stable' option preserves the input order, if that's important for your application).

unique(A, 'rows', 'stable')

[Ruchi Bhatia]

Thanks. Wow, didn't realize it was that straight forward.

Answer 2

[Image Analyst]

Try unique() with the 'rows' option:

uniqueRowsOfA = unique(A, 'rows')

[Ruchi Bhatia]

thank you

Answer 3

[Kaushik Lakshminarasimhan]

Did you try this?

[C,IA] = unique(A,'rows');

C contains all unique rows of A. IA contains the indices of the rows of A that are in C. So if you want the indices of the rows that were removed, you can use:

[nrows,~] = size(A);
notIA = setdiff(1:nrows,IA); % duplicate rows

[Ruchi Bhatia]

Thank you! Very helpful.