octave-lyh: scripts/statistics/base/std.m annotate

annotate scripts/statistics/base/std.m @ 14138:72c96de7a403 stable

maint: update copyright notices for 2012

author	John W. Eaton <jwe@octave.org>
date	Mon, 02 Jan 2012 14:25:41 -0500
parents	645a87434fcb
children	34af9f9ff98b

rev	line source
14138 72c96de7a403 maint: update copyright notices for 2012 John W. Eaton <jwe@octave.org> parents: 12781 diff changeset	1 ## Copyright (C) 1996-2012 John W. Eaton
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	2 ##
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	3 ## This file is part of Octave.
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	4 ##
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	5 ## Octave is free software; you can redistribute it and/or modify it
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	6 ## under the terms of the GNU General Public License as published by
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6754 diff changeset	7 ## the Free Software Foundation; either version 3 of the License, or (at
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6754 diff changeset	8 ## your option) any later version.
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	9 ##
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	10 ## Octave is distributed in the hope that it will be useful, but
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	13 ## General Public License for more details.
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	14 ##
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	15 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6754 diff changeset	16 ## along with Octave; see the file COPYING. If not, see
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6754 diff changeset	17 ## <http://www.gnu.org/licenses/>.
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	18
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	19 ## -- texinfo --
10793 be55736a0783 Grammarcheck the documentation from m-files. Rik <octave@nomad.inbox5.com> parents: 9500 diff changeset	20 ## @deftypefn {Function File} {} std (@var{x})
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	21 ## @deftypefnx {Function File} {} std (@var{x}, @var{opt})
9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	22 ## @deftypefnx {Function File} {} std (@var{x}, @var{opt}, @var{dim})
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	23 ## Compute the standard deviation of the elements of the vector @var{x}.
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	24 ## @tex
0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	25 ## $$
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	26 ## {\rm std} (x) = \sigma = \sqrt{{\sum_{i=1}^N (x_i - \bar{x})^2 \over N - 1}}
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	27 ## $$
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	28 ## where $\bar{x}$ is the mean value of $x$ and $N$ is the number of elements.
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	29 ## @end tex
6754 451b346d8c2f [project @ 2007-06-25 17:31:46 by jwe] jwe parents: 6046 diff changeset	30 ## @ifnottex
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3408 diff changeset	31 ##
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	32 ## @example
0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	33 ## @group
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	34 ## std (x) = sqrt ( 1/(N-1) SUM_i (x(i) - mean(x))^2 )
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	35 ## @end group
0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	36 ## @end example
10821 693e22af08ae Grammarcheck documentation of m-files Rik <octave@nomad.inbox5.com> parents: 10793 diff changeset	37 ##
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	38 ## @noindent
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	39 ## where @math{N} is the number of elements.
6754 451b346d8c2f [project @ 2007-06-25 17:31:46 by jwe] jwe parents: 6046 diff changeset	40 ## @end ifnottex
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	41 ##
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	42 ## If @var{x} is a matrix, compute the standard deviation for
0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	43 ## each column and return them in a row vector.
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	44 ##
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	45 ## The argument @var{opt} determines the type of normalization to use.
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	46 ## Valid values are
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	47 ##
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	48 ## @table @asis
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	49 ## @item 0:
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	50 ## normalize with @math{N-1}, provides the square root of the best unbiased
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	51 ## estimator of the variance [default]
10821 693e22af08ae Grammarcheck documentation of m-files Rik <octave@nomad.inbox5.com> parents: 10793 diff changeset	52 ##
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	53 ## @item 1:
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	54 ## normalize with @math{N}, this provides the square root of the second
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	55 ## moment around the mean
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	56 ## @end table
9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	57 ##
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	58 ## If the optional argument @var{dim} is given, operate along this dimension.
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	59 ## @seealso{var, range, iqr, mean, median}
3367 0748b03c3510 [project @ 1999-11-20 14:52:38 by jwe] jwe parents: 3200 diff changeset	60 ## @end deftypefn
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	61
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	62 ## Author: jwe
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	63
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	64 function retval = std (x, opt = 0, dim)
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	65
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	66 if (nargin < 1 \|\| nargin > 3)
6046 34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe] jwe parents: 6024 diff changeset	67 print_usage ();
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	68 endif
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	69
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	70 if (! (isnumeric (x) \|\| islogical (x)))
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	71 error ("std: X must be a numeric vector or matrix");
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	72 endif
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	73
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	74 if (isempty (opt))
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	75 opt = 0;
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	76 endif
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	77 if (opt != 0 && opt != 1)
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	78 error ("std: normalization OPT must be 0 or 1");
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	79 endif
e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	80
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	81 nd = ndims (x);
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	82 sz = size (x);
9500 bb37822e9b82 std.m: correctly work along singleton dimension John W. Eaton <jwe@octave.org> parents: 9211 diff changeset	83 if (nargin < 3)
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	84 ## Find the first non-singleton dimension.
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	85 (dim = find (sz > 1, 1)) \|\| (dim = 1);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	86 else
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	87 if (!(isscalar (dim) && dim == fix (dim))
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	88 \|\| !(1 <= dim && dim <= nd))
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	89 error ("std: DIM must be an integer and a valid dimension");
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 7411 diff changeset	90 endif
4844 9f7ef92b50b0 [project @ 2004-04-02 17:26:53 by jwe] jwe parents: 3426 diff changeset	91 endif
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	92
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	93 n = sz(dim);
12781 645a87434fcb std.m: Allow null inputs []. Bug #33532. Rik <octave@nomad.inbox5.com> parents: 12656 diff changeset	94 if (n == 1 \|\| isempty (x))
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	95 if (isa (x, 'single'))
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	96 retval = zeros (sz, 'single');
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	97 else
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	98 retval = zeros (sz);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	99 endif
12781 645a87434fcb std.m: Allow null inputs []. Bug #33532. Rik <octave@nomad.inbox5.com> parents: 12656 diff changeset	100 else
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	101 retval = sqrt (sumsq (center (x, dim), dim) / (n - 1 + opt));
3200 781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	102 endif
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	103
781c930425fd [project @ 1998-10-29 05:23:08 by jwe] jwe parents: diff changeset	104 endfunction
7411 83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	105
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	106
7411 83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	107 %!test
83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	108 %! x = ones (10, 2);
83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	109 %! y = [1, 3];
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	110 %! assert(std (x) == [0, 0]);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	111 %! assert(std (y), sqrt (2), sqrt (eps));
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	112 %! assert(std (x, 0, 2), zeros (10, 1));
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	113
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	114 %!assert(std (ones (3, 1, 2), 0, 2), zeros (3, 1, 2));
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	115 %!assert(std ([1 2], 0), sqrt(2)/2, 5*eps);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	116 %!assert(std ([1 2], 1), 0.5, 5*eps);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	117 %!assert(std(1), 0);
6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	118 %!assert(std(single(1)), single(0));
12781 645a87434fcb std.m: Allow null inputs []. Bug #33532. Rik <octave@nomad.inbox5.com> parents: 12656 diff changeset	119 %!assert(std([]), []);
645a87434fcb std.m: Allow null inputs []. Bug #33532. Rik <octave@nomad.inbox5.com> parents: 12656 diff changeset	120 %!assert(std(ones (1,3,0,2)), ones (1,3,0,2));
7411 83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	121
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	122 %% Test input validation
7411 83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	123 %!error std ();
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	124 %!error std (1, 2, 3, 4);
12656 6b2f14af2360 Overhaul functions in statistics/base directory. Rik <octave@nomad.inbox5.com> parents: 11587 diff changeset	125 %!error std (['A'; 'B'])
11436 e151e23f73bc Overhaul base statistics functions and documentation of same. Rik <octave@nomad.inbox5.com> parents: 10821 diff changeset	126 %!error std (1, -1);
7411 83a8781b529d [project @ 2008-01-22 21:52:25 by jwe] jwe parents: 7017 diff changeset	127

Mercurial > hg > octave-lyh

annotate scripts/statistics/base/std.m @ 14138:72c96de7a403 stable