## find nonzero-middle point of an array

on 1 May 2013

### Azzi Abdelmalek (view profile)

Hello,

example

a=[0,0,3,4,5];

I want a function that give me middle point of nonzero element which is 4

not 3 which is the middle point of the array.

Thank you!

### Azzi Abdelmalek (view profile)

on 1 May 2013

```idx=find(a);
out=a(idx(round(numel(idx)/2)))
```

### Walter Roberson (view profile)

on 1 May 2013

``` t = nonzeros(a);
t(ceil(end/2))```

floor() cannot be used instead of ceil(): if there was only 1 non-zero element, end would be 1, end/2 would be 1/2, floor(1/2) would be 0, and there is no element #0.

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Jan Simon

### Jan Simon (view profile)

on 1 May 2013

@Tiger: You can vote for Walter's answer, if it helps you. And you can ask Azzi to delete his answer and resubmit it. Then the status of acceptance is cleared and you can choose again.

Walter Roberson

### Walter Roberson (view profile)

on 1 May 2013

Azzi's answer will work, as round() of an integer is the integer itself and round() of (integer + 1/2) is the next integer: this is the same set of results as ceil() of the integer and of (integer + 1/2)

Azzi Abdelmalek

### Azzi Abdelmalek (view profile)

on 1 May 2013

If someone asks me to delete my answer, I do not think I will do it.