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

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Eddy Iswardi
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]

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Answers (3)

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

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Ameer Hamza
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;

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J. Alex Lee
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?

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

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

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

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