MATLAB: How to make a column vector of 2 distinct numbers

Question

How can I make a 400×1 column vector in the following format..

first 100 rows = all 1's

101st to 400th row = all 2's

I am a matlab newbie so any help to get me started will be greatly appreciated.

Thanks

Answer 1

Many possible solutions

V = [ones(100,1);2*ones(300,1)];
or 
V = [repmat(1,100,1);repmat(2,300,1)];
or
V = ones(400,1); V(101:end)=2;
or
V(1:100,1)=1;V(101:400,1)=2;