# How to find the another values in array

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singh on 18 Apr 2015
Edited: Stephen23 on 4 May 2015
Suppose I have a array A=
1 73.21 32.2
6 11.1 3.32
9 30.4 19.64
17 12.6 77.3
20 30.7 6.2
23 21 .9 42.5
Now I have another array which contain some values B =
1 9 20 23
Now I input a single no through input command called N=20
I wish to find that N(20) in column first and return corresponding values column second and column third in array A
Like it return value 30.7 and 6.2
pfb on 18 Apr 2015
Thanks for choosing my answer.
Anyway the other two other answers are perhaps better, in that they do not use "find".

pfb on 18 Apr 2015
You could use the command "find".
% this finds the row (if any) at which N appears in the first column of A
r = find(A(:,1)==N);
% this returns the corresponding values in the 2nd and 3rd columns of A
v = A(r,[2 3]);
% note that this is a row vector if N appears only once in the first column of A
% It is a matrix if N appears more than once
% It is an empty vector if N never appears.
Stephen23 on 4 May 2015
Edited: Stephen23 on 4 May 2015
find is slower and not at all required. Use Image Analyst's solution.

### More Answers (1)

Image Analyst on 18 Apr 2015
Just use logical indexing. You don't even need find().
A=[...
1, 73.21, 32.2;
6, 11.1, 3.32;
9, 30.4, 19.64;
17, 12.6, 77.3;
20, 30.7, 6.2;
23, 21.9, 42.5]
% B is unused - not sure why it was even mentioned
B =[1 9 20 23];
N = 20; % Gotten from using the input() function.
row = A(:,1)==N % N must be an integer.
output = A(row, 2:3)