Octave / Matlab: Extend a vector making it repeat itself?

Question

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]

Solution 1

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

v10 = repmat(v, 1, 5)

Solution 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))

Comments

[EIIPII]

link to octave documentation: http://www.gnu.org/software/octave/doc/interpreter/Special-U‌​tility-Matrices.html‌​#Special-Utility-Mat‌​rices

[Cris Luengo]

Please don’t duplicate answers. Instead, leave a comment under the question pointing to this answer. Also, as per my comment there from 3 years ago, this method was no longer faster then.