# How to add the value of the 3 highest elements automatically from a vector?

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Eddy Iswardi on 28 Mar 2020
Commented: Peng Li on 28 Mar 2020
I want to add the 3 highest elements of 'y' to 'sk'. But I don't know what code to use to automatically add them. in this case, the elements in question are 12, 12, and 13. So that the value will be 12 + 9 = 21, 12 + 9 = 21, 13 + 9 = 22. This is my code
clc;
clear all;
x1=[1 2 3 4 5 6 7 8 9 10 11];
x2=[1 2 3 4 5 6 7 8 9 10 11];
y=[10 9 11 10 11 11 9 10 12 12 13];
sx=9;
and the result will be
y = [10 9 11 10 11 11 9 10 21 21 22]

Peng Li on 28 Mar 2020
[~, ind] = sort(y);
y(ind(end-2, end)) = y(ind(ind-2, end)) + ax;

Show 1 older comment
Ameer Hamza on 28 Mar 2020
There is a few typos in Peng's code. try it like this
[~, ind] = sort(y);
y(ind(end-2:end)) = y(ind(end-2:end)) + sx;
or like this with a bit simple indexing
[~, ind] = sort(y, 'descend');
y(ind(1:3)) = y(ind(1:3)) + sx;
Eddy Iswardi on 28 Mar 2020
oke, thank you. It's work now.
Peng Li on 28 Mar 2020
Thanks Ameer. Using cell phone lol

J. Alex Lee on 28 Mar 2020
like this?
[~,idx] = maxk(y,3)
y(idx) = y(idx) + sx
Are x1 and x2 irrelevant to your question?

#### 1 Comment

Eddy Iswardi on 28 Mar 2020
I get an error at 'maxk'
Undefined function or variable 'maxk'.
I use matlab 2016a

Torsten on 28 Mar 2020
[~,idx]=maxk(y,3);
y(idx)=y(idx)+sx;
y

Eddy Iswardi on 28 Mar 2020
I get an error at 'maxk'
Undefined function or variable 'maxk'.
I use matlab 2016a
Torsten on 28 Mar 2020
[~,idx] = sort(y,'descend');
y(idx(1:3))=y(idx(1:3))+sx;
y
Eddy Iswardi on 28 Mar 2020
oke, thank you. It's work now.

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