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

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]

Answer 1

[Peng Li]

[~, ind] = sort(y);

y(ind(end-2, end)) = y(ind(ind-2, end)) + ax;

Should meet your need.

[Eddy Iswardi]

sorry, but it's not working

[Ameer Hamza]

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]

oke, thank you. It's work now.

[Peng Li]

Thanks Ameer. Using cell phone lol

Answer 2

[J. Alex Lee]

like this?

[~,idx] = maxk(y,3)
y(idx) = y(idx) + sx

Are x1 and x2 irrelevant to your question?

[Eddy Iswardi]

I get an error at 'maxk'

Undefined function or variable 'maxk'.

I use matlab 2016a

Answer 3

[Torsten]

[~,idx]=maxk(y,3);

y(idx)=y(idx)+sx;

y

[Eddy Iswardi]

I get an error at 'maxk'

Undefined function or variable 'maxk'.

I use matlab 2016a

[Torsten]

[~,idx] = sort(y,'descend');

y(idx(1:3))=y(idx(1:3))+sx;

y

[Eddy Iswardi]

oke, thank you. It's work now.