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find nonzero-middle point of an array

Asked by Tiger

Tiger

on 1 May 2013
Accepted Answer by Azzi Abdelmalek

Azzi Abdelmalek

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!

0 Comments

Tiger

Tiger

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2 Answers

Answer by Azzi Abdelmalek

Azzi Abdelmalek

on 1 May 2013
Accepted answer
idx=find(a);
out=a(idx(round(numel(idx)/2)))

0 Comments

Azzi Abdelmalek

Azzi Abdelmalek

Answer by Walter Roberson

Walter Roberson

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.

4 Comments

Jan Simon

Jan Simon

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

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

on 1 May 2013

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

Walter Roberson

Walter Roberson

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