How do I generate a vector of ordered integer

I want to generate a vector of the form [1 2 3 1 2 3 4 5 1 2 3 4 5 6 7 1 2 3 4 5 6 7 9] with simple matlab code.

Answer 1

[the cyclist]

One way:

x = [1 2 3 1 2 3 4 5 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9];

But I'm guessing that's not what you meant.

Another way:

x = [];
for k = 3:2:9
  x = [x, 1:k]
end

In general, it is not a good idea to "grow" a vector like this, by simply appending. It's better to define the vector length ahead of time, preallocating the memory. But, I'm feeling lazy right now.