How to make a column vector of 2 distinct numbers

How can I make a 400x1 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

[Konstantinos Sofos]

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;

Answer 2

[the cyclist]

One way:

x = ones(400,1);
x(101:400) = 2;

[Dubstep Dublin]

Thank you for your reply. Is there any way of implementing it without the use of 'ones' function such that I can make such an array of different numbers (suppose say 172 instead of 1 and 272 instead of 2)

Answer 3

[the cyclist]

One way:

x = [repmat(1,[100 1]); repmat(2,[300 1])];

Answer 4

[James Tursa]

[ones(100,1);2*ones(300,1)]