getting even elements from vector

i'm trying to create new vector from another vector with only the odd elements of the of vectorr. i tried this:

for i=length(q1)

if mod(i,2)==0

a1(i,:)=q1(i,:);

else

a1(i,:)=[];

end

end

when q1 is the old vector and a1 is the new one and q1 is a column vector so i'm trying to duplicate his even row's

Answer 1

[KSSV]

You can extract the even indices and odd indices at one stretch without loop.

k = rand(1,10) ;
% even index values
iwant_even = k(2:2:end) ;
% odd index values
iwant_odd = k(1:2:end) ;

[avner yakov]

thanks allot

[Om Yadav]

This is a good answer. This is what I was looking for. A word of advice, avoid using for loop as much as possible in MATLAB, make use of vectorization instead. MATLAB is made for this.

[carlos edurdo condori ochoa]

That is a good way to think KSSV