How To Remove Repeating Pattern From Vector

Suppose I have a vector that looks like this:

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

You can see the repeating pattern of four-by-four. Is there a command that can shave this down to something like this?...

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

I checked "decimate" but I don't think it does what I want. Yes, I could construct an IF statement, but I was hoping there was a "one-liner" that might do it quickly and easily.

Thanks in advance!

M Ridzon

Answer 1

[John D'Errico]

x(find(diff(x) == 0) + 1) = [];

That just drops out the consecutive reps, changing x.

If you want to create a new vector, you might have done this:

xx = x([true;diff(x)~=0]);