how do I remove rows with duplicated values?

let say i have matrix A
A = [1 2 3 4 5;
3 5 7 9 11;
1 1 4 5 7;
3 5 6 6 9;
1 4 10 15 16]
and wanted to remove all rows with values that repeated with each other. Then A will become
A = [1 2 3 4 5;
3 5 7 9 11;
1 4 10 15 16]
Thanks for the help in Advance

 Accepted Answer

Here is a one-liner:
A(any(diff(sort(A,2),[],2)==0,2),:)=[];
If you are certain that each row is already in numerical order (as in your example), you can skip the sorting step.
The algorithm is the following:
  • Use sort to sort the values in each row
  • Use diff to get the difference between consecutive values in each row
  • Use any to check if any of those differences equal zero (indicating a duplicate values)
  • Use the output of the any command, which is a logical index, to delete the rows that have duplicates

3 Comments

Thanks yea it was already sort it out. So i only needed diff and any.
Works perfectly. Thank you
Nice programming there!

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