/usr/share/octave/packages/3.2/nan-2.4.4/var.m is in octave-nan 2.4.4-1.
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 | function y=var(x,opt,DIM,W)
% VAR calculates the variance.
%
% y = var(x [, opt[, DIM]])
% calculates the variance in dimension DIM
% the default DIM is the first non-single dimension
%
% opt 0: normalizes with N-1 [default]
% 1: normalizes with N
% DIM dimension
% 1: VAR of columns
% 2: VAR of rows
% N: VAR of N-th dimension
% default or []: first DIMENSION, with more than 1 element
% W weights to compute weighted variance (default: [])
% if W=[], all weights are 1.
% number of elements in W must match size(x,DIM)
%
% usage:
% var(x)
% var(x, opt, DIM)
% var(x, [], DIM)
% var(x, W, DIM)
% var(x, opt, DIM, W)
%
% features:
% - can deal with NaN's (missing values)
% - weighting of data
% - dimension argument
% - compatible to Matlab and Octave
%
% see also: MEANSQ, SUMSQ, SUMSKIPNAN, MEAN, RMS, STD,
% 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/>.
% $Id: var.m 8223 2011-04-20 09:16:06Z schloegl $
% Copyright (C) 2000-2003,2006,2009,2010 by Alois Schloegl <alois.schloegl@gmail.com>
% This is part of the NaN-toolbox for Octave and Matlab
% http://pub.ist.ac.at/~schloegl/matlab/NaN/
if nargin<3,
DIM = [];
end;
if nargin==1,
W = [];
opt = [];
elseif any(nargin==[2,3])
if (numel(opt)<2),
W = [];
else
W = opt;
opt = [];
end;
elseif (nargin==4) && (numel(opt)<2) && (numel(DIM)<2),
;
else
fprintf(1,'Error VAR: incorrect usage\n');
help var;
return;
end;
if isempty(opt),
opt = 0;
end;
if isempty(DIM),
DIM = find(size(x)>1,1);
if isempty(DIM), DIM=1; end;
end;
[y,n,ssq] = sumskipnan(x,DIM,W);
if all(ssq(:).*n(:) > 2*(y(:).^2)),
%% rounding error is neglectable
y = ssq - y.*y./n;
else
%% rounding error is not neglectable
szx = size(x);
szy = size(y);
if length(szy)<length(szx);
szy(length(szy)+1:length(szx)) = 1;
end;
[y,n] = sumskipnan((x-repmat(y./n,szx./szy)).^2,DIM,W);
end;
if (opt~=1)
n = max(n-1,0); % in case of n=0 and n=1, the (biased) variance, STD and STE are INF
end;
y = y./n; % normalize
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