How to find a specific row in a matrix and eliminate it?

Hi everyone, I have a matrix such as this: D0=[1 2;1 4;2 1;3 5;4 1;5 3]. I need to eliminate one of the two rows with same elements. for example, 1 & 2 both involve in rows one and three, so I need to eliminate one of these rows. can any one please help me?

Answer 1

[Guillaume]

It looks like you don't care about the ordering of the columns. In that case, it's extremely simple: a) sort the rows (so that [2 1] becomes [1 2]) and b) use unique to remove duplicates

D0 = [1 2;1 4;2 1;3 5;4 1;5 3]
uniquerows = unique(sort(D0, 2), 'rows', 'stable') 
%if you don't care about the rows ordering you can omit the 'stable'

[kyana shayan]

wow, it perfectly works. awesome, thank u.

[kyana shayan]

one more thing, if the matrix has 3 columns, then sorting will disorder the original matrix. for example, if I use unique function on this matrix: D0=[2 1 4;4 1 2] ,the uniquerows will be: uniquerows=[1 2 4]. but I need [2 1 4] or [4 1 2]. Guillaume,can you give me a hint on this,too ?

[Guillaume]

Simply use the second return value of unique to get the indices of the rows that have been kept. Use those indices to get the actual rows:

D0 = [1 2 4;1 4 3;2 1 4;3 5 2;4 1 3;5 3 2]
[~, rowindices] = unique(sort(D0, 2), 'rows'); %'stable' optional
uniquerows = D0(rowindices, :)