Octave / Matlab: Extend a vector making it repeat

问题:

Is there a way to extend a vector by making it repeat itself?

>v = [1 2];
>v10 = v x 5; %x represents some function. Something like "1 2" x 5 in perl

Then v10 would be:

>v10
     1 2 1 2 1 2 1 2 1 2

This should work for the general case, not just for [1 2]

回答1:

The function you're looking for is repmat().

v10 = repmat(v, 1, 5)

回答2:

Obviously repmat is the way to go if you know in which direction you want to expand the vector.

However, if you want a general solution that always repeats the vector in the longest direction, this combination of repmat and indexing should do the trick:

 v10=v(repmat(1:length(v),1,5))