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# How to delete repeated rows without using unique function?

Asked by Connor on 23 Apr 2013

I am looking for a way to delete repeated rows without using the unique function. For example if I have the matrix

A=[2 4 8; 8 2 4; 3 3 -6]

one of the first two rows needs to be deleted. Order doesn't need to be kept. I'm sure I need to use sort, and maybe find or diff. I'm not exactly sure how to go about it.

Any and all help is appreciated!

the cyclist on 23 Apr 2013

Guessing this is homework. That's the usual motivator for not wanting to use particular functions.

Matt Kindig on 23 Apr 2013

It's strange that you consider the first two rows of A to be "repeated", since the order of the elements is different (one is a permutation of the other). Is this what you want?

Connor on 23 Apr 2013

They are considered repeated because order isn't important here. This is a very small part for my project, and isn't required. My professor said if we could do this we could get some extra credit. Thanks!

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Answer by Matt J on 23 Apr 2013
Edited by Matt J on 23 Apr 2013

Hint:

`   >> sortrows(sort(A,2))`
```ans =
```
```      -6     3     3
2     4     8
2     4     8```

You should now find diff() rather helpful.