Check if a number in a matrix's first column exist. If yes then keep that entire row in a separate matrix

I have a 5x3 matrix. I want to scan through the first column of the matrix for a particular number. If that particular number exsit then I want that entire row of the matrix in a sepreate matrix called results.

example: give the matrix

example = [9,8.16,8.17;16,12.36,12.36;23,40.69,27;30,5.66,103.41;9,25.21,122.96]

%     9    8.1600    8.1700
%    16   12.3600   12.3600
%    23   40.6900   27.0000
%    30    5.6600  103.4100
%     9   25.2100  122.9600

if we search for number 9 in the first column (only the first column) then the resultunt new matrix should be

result =
9    8.1600    8.1700
9   25.2100  122.960

Anyhelp would be greatly appreciated. Thank you

best regards

Answer 1

[KSSV]

A = [     9    8.1600    8.1700
    16   12.3600   12.3600
    23   40.6900   27.0000
    30    5.6600  103.4100
     9   25.2100  122.9600] ;
 
 iwant = A(A(:,1)==9,:)

If you have multiple number to pick use ismember

 
 B = [9 ; 16] ;  
 [idx,ia] = ismember(A(:,1),B)
 iwant = A(idx,:)

[Ahsan]

thank u. works perfectly.

cheers