This file is indexed.

/usr/share/octave/packages/statistics-1.3.0/raylrnd.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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
## Copyright (C) 2006, 2007 Arno Onken <asnelt@asnelt.org>
##
## 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{x} =} raylrnd (@var{sigma})
## @deftypefnx {Function File} {@var{x} =} raylrnd (@var{sigma}, @var{sz})
## @deftypefnx {Function File} {@var{x} =} raylrnd (@var{sigma}, @var{r}, @var{c})
## Generate a matrix of random samples from the Rayleigh distribution.
##
## @subheading Arguments
##
## @itemize @bullet
## @item
## @var{sigma} is the parameter of the Rayleigh distribution. The elements
## of @var{sigma} must be positive.
##
## @item
## @var{sz} is the size of the matrix to be generated. @var{sz} must be a
## vector of non-negative integers.
##
## @item
## @var{r} is the number of rows of the matrix to be generated. @var{r} must
## be a non-negative integer.
##
## @item
## @var{c} is the number of columns of the matrix to be generated. @var{c}
## must be a non-negative integer.
## @end itemize
##
## @subheading Return values
##
## @itemize @bullet
## @item
## @var{x} is a matrix of random samples from the Rayleigh distribution with
## corresponding parameter @var{sigma}. If neither @var{sz} nor @var{r} and
## @var{c} are specified, then @var{x} is of the same size as @var{sigma}.
## @end itemize
##
## @subheading Examples
##
## @example
## @group
## sigma = 1:6;
## x = raylrnd (sigma)
## @end group
##
## @group
## sz = [2, 3];
## x = raylrnd (0.5, sz)
## @end group
##
## @group
## r = 2;
## c = 3;
## x = raylrnd (0.5, r, c)
## @end group
## @end example
##
## @subheading References
##
## @enumerate
## @item
## Wendy L. Martinez and Angel R. Martinez. @cite{Computational Statistics
## Handbook with MATLAB}. Appendix E, pages 547-557, Chapman & Hall/CRC,
## 2001.
##
## @item
## Athanasios Papoulis. @cite{Probability, Random Variables, and Stochastic
## Processes}. pages 104 and 148, McGraw-Hill, New York, second edition,
## 1984.
## @end enumerate
## @end deftypefn

## Author: Arno Onken <asnelt@asnelt.org>
## Description: Random samples from the Rayleigh distribution

function x = raylrnd (sigma, r, c)

  # Check arguments
  if (nargin == 1)
    sz = size (sigma);
  elseif (nargin == 2)
    if (! isvector (r) || any ((r < 0) | round (r) != r))
      error ("raylrnd: sz must be a vector of non-negative integers")
    endif
    sz = r(:)';
    if (! isscalar (sigma) && ! isempty (sigma) && (length (size (sigma)) != length (sz) || any (size (sigma) != sz)))
      error ("raylrnd: sigma must be scalar or of size sz");
    endif
  elseif (nargin == 3)
    if (! isscalar (r) || any ((r < 0) | round (r) != r))
      error ("raylrnd: r must be a non-negative integer")
    endif
    if (! isscalar (c) || any ((c < 0) | round (c) != c))
      error ("raylrnd: c must be a non-negative integer")
    endif
    sz = [r, c];
    if (! isscalar (sigma) && ! isempty (sigma) && (length (size (sigma)) != length (sz) || any (size (sigma) != sz)))
      error ("raylrnd: sigma must be scalar or of size [r, c]");
    endif
  else
    print_usage ();
  endif

  if (! isempty (sigma) && ! ismatrix (sigma))
    error ("raylrnd: sigma must be a numeric matrix");
  endif

  if (isempty (sigma))
    x = [];
  elseif (isscalar (sigma) && ! (sigma > 0))
    x = NaN .* ones (sz); 
  else
    # Draw random samples
    x = sqrt (-2 .* log (1 - rand (sz)) .* sigma .^ 2);

    # Continue argument check
    k = find (! (sigma > 0));
    if (any (k))
      x(k) = NaN;
    endif
  endif

endfunction

%!test
%! sigma = 1:6;
%! x = raylrnd (sigma);
%! assert (size (x), size (sigma));
%! assert (all (x >= 0));

%!test
%! sigma = 0.5;
%! sz = [2, 3];
%! x = raylrnd (sigma, sz);
%! assert (size (x), sz);
%! assert (all (x >= 0));

%!test
%! sigma = 0.5;
%! r = 2;
%! c = 3;
%! x = raylrnd (sigma, r, c);
%! assert (size (x), [r, c]);
%! assert (all (x >= 0));