1 ## Copyright (C) 2005-2012 Paul Kienzle
3 ## This file is part of Octave.
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 3 of the License, or (at
8 ## your option) any later version.
10 ## Octave is distributed in the hope that it will be useful, but
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ## General Public License for more details.
15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>.
20 ## @deftypefn {Function File} {[count, value] =} runlength (@var{x})
21 ## Find the lengths of all sequences of common values. Return the
22 ## vector of lengths and the value that was repeated.
26 ## runlength ([2, 2, 0, 4, 4, 4, 0, 1, 1, 1, 1])
27 ## @result{} [2, 1, 3, 1, 4]
32 function [count, value] = runlength (x)
38 if (!(isnumeric (x) || islogical (x)) || !isvector (x))
39 error ("runlength: X must be a numeric vector");
46 idx = [find(x(1:end-1) != x(2:end)), length(x)];
47 count = diff ([0 idx]);
55 %!assert (runlength([2 2 0 4 4 4 0 1 1 1 1]), [2 1 3 1 4]);
56 %!assert (runlength([2 2 0 4 4 4 0 1 1 1 1]'), [2 1 3 1 4]);
58 %! [c, v] = runlength ([2 2 0 4 4 4 0 1 1 1 1]);
59 %! assert (c, [2 1 3 1 4]);
60 %! assert (v, [2 0 4 0 1]);
62 %% Test input validation
64 %!error runlength (1, 2)
65 %!error runlength (['A'; 'B'])
66 %!error runlength (ones(2,2))