# How to choose values ​​in the second and third column corresponding to the drawn numbers?

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hawk5577 on 15 Nov 2018
Answered: Bruno Luong on 17 Nov 2018
%N X Y
AA=[ 1 0 4
2 1 5
21 4 6
81 3 7
92 7 8
73 6 4
65 3 3
36 5 4
16 6 5
6 7 4]
A=AA(:,1);
disp(A);
b=(A(randperm(size(A,1),3),1))
disp(b);
% How to choose values ​​in the second and third column corresponding to the drawn numbers?
for i=1:3 %This solution give me error - Index in position 1 exceeds array bounds (must not exceed 10).
c=b(i,1);
disp(AA(c,2));
disp(AA(c,3));
end

Arunkumar M on 17 Nov 2018
Edited: madhan ravi on 17 Nov 2018
Error occurs because with c you are finding the element which is a part of first column in AA. But this element is not the index. So you have to find the index where it is located and then pull out second and third column values.
for i=1:3
c=b(i,1);
temp1 = find(A == c);
temp2 = temp1(1,1); % in case multiple values are returned in temp1.
disp(AA(temp2,2));
disp(AA(temp2,3));
end
##### 2 CommentsShowHide 1 older comment
Arunkumar M on 17 Nov 2018
Is temp1 empty?

Bruno Luong on 17 Nov 2018
Why make so complicated? RANDPERM returns the position, store and use it rather than trying to recover it.
AA=[ 1 0 4
2 1 5
21 4 6
81 3 7
92 7 8
73 6 4
65 3 3
36 5 4
16 6 5
6 7 4]
p = randperm(size(A,1),3);
b = AA(p,1)
AA(p,:)