/usr/share/octave/packages/statistics-1.3.0/runstest.m is in octave-statistics 1.3.0-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | ## Copyright (C) 2013 Nir Krakauer <nkrakauer@ccny.cuny.edu>
##
## This program is free software; you can redistribute it and/or modify it under
## the terms of the GNU General Public License as published by the Free Software
## Foundation; either version 3 of the License, or (at your option) any later
## version.
##
## This program is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
## details.
##
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {Function File} {@var{h}, @var{p}, @var{stats} =} runstest (@var{x}, @var{v})
## Runs test for detecting serial correlation in the vector @var{x}.
##
## @subheading Arguments
##
## @itemize @bullet
## @item
## @var{x} is the vector of given values.
## @item
## @var{v} is the value to subtract from @var{x} to get runs (defaults to @code{median(x)})
## @end itemize
##
## @subheading Return values
##
## @itemize @bullet
## @item
## @var{h} is true if serial correlation is detected at the 95% confidence level (two-tailed), false otherwise.
## @item
## @var{p} is the probablity of obtaining a test statistic of the magnitude found under the null hypothesis of no serial correlation.
## @item
## @var{stats} is the structure containing as fields the number of runs @var{nruns}; the numbers of positive and negative values of @code{x - v}, @var{n1} and @var{n0}; and the test statistic @var{z}.
##
## @end itemize
##
## Note: the large-sample normal approximation is used to find @var{h} and @var{p}. This is accurate if @var{n1}, @var{n0} are both greater than 10.
##
## Reference:
## NIST Engineering Statistics Handbook, 1.3.5.13. Runs Test for Detecting Non-randomness, http://www.itl.nist.gov/div898/handbook/eda/section3/eda35d.htm
##
## @seealso{}
## @end deftypefn
## Author: Nir Krakauer <nkrakauer@ccny.cuny.edu>
## Description: Runs test for detecting serial correlation
function [h, p, stats] = runstest (x, x2)
# Check arguments
if (nargin < 1)
print_usage;
endif
if nargin > 1 && isnumeric(x2)
v = x2;
else
v = median(x);
endif
x = x(~isnan(x)); #delete missing values
x = sign(x - v);
x = x(x ~= 0); #delete any zeros
R = sum((x(1:(end-1)) .* x(2:end)) < 0) + 1; #number of runs
#expected number of runs for an iid sequence
n1 = sum(x > 0);
n2 = sum(x < 0);
R_bar = 1 + 2*n1*n2/(n1 + n2);
#standard deviation of number of runs for an iid sequence
s_R = sqrt(2*n1*n2*(2*n1*n2 - n1 - n2)/((n1 + n2)^2 * (n1 + n2 - 1)));
#desired significance level
alpha = 0.05;
Z = (R - R_bar) / s_R; #test statistic
p = 2 * normcdf(-abs(Z));
h = p < alpha;
if nargout > 2
stats.nruns = R;
stats.n1 = n1;
stats.n0 = n2;
stats.z = Z;
endif
endfunction
%!test
%! data = [-213 -564 -35 -15 141 115 -420 -360 203 -338 -431 194 -220 -513 154 -125 -559 92 -21 -579 -52 99 -543 -175 162 -457 -346 204 -300 -474 164 -107 -572 -8 83 -541 -224 180 -420 -374 201 -236 -531 83 27 -564 -112 131 -507 -254 199 -311 -495 143 -46 -579 -90 136 -472 -338 202 -287 -477 169 -124 -568 17 48 -568 -135 162 -430 -422 172 -74 -577 -13 92 -534 -243 194 -355 -465 156 -81 -578 -64 139 -449 -384 193 -198 -538 110 -44 -577 -6 66 -552 -164 161 -460 -344 205 -281 -504 134 -28 -576 -118 156 -437 -381 200 -220 -540 83 11 -568 -160 172 -414 -408 188 -125 -572 -32 139 -492 -321 205 -262 -504 142 -83 -574 0 48 -571 -106 137 -501 -266 190 -391 -406 194 -186 -553 83 -13 -577 -49 103 -515 -280 201 300 -506 131 -45 -578 -80 138 -462 -361 201 -211 -554 32 74 -533 -235 187 -372 -442 182 -147 -566 25 68 -535 -244 194 -351 -463 174 -125 -570 15 72 -550 -190 172 -424 -385 198 -218 -536 96]; #NIST beam deflection data, http://www.itl.nist.gov/div898/handbook/eda/section4/eda425.htm
%! [h, p, stats] = runstest (data);
%! expected_h = true;
%! expected_p = 0.0070646;
%! expected_z = 2.6938;
%! assert (h, expected_h);
%! assert (p, expected_p, 1E-6);
%! assert (stats.z, expected_z, 1E-4);
|