sir, i generate the list of cluster-heads and corresponding there energy but now i want to extract the energy with corresponding cluster-id according to lower energy cluster-heads, medium energy cluster-heads,higher energy groups, how do it..?

Ex- CH-ID ENERGY 12 1.2J 14 5.5 25 2.5J here the extract the energy by threshold like all the energy group, while(energy<=2.6) but it not give the corresponding ID .

Answer 1

[KSSV]

E = [ 12 1.2 14 5.5 25 2.5] ;
idx = E<2.6 ;

The above gives logical indices where energy is less then 2.6. If you want the indices use find .

idx = find(E<2.6) ;

But it suggested and better to use logical indexing rather then find.