Mercurial > hg > octave-lyh
annotate scripts/statistics/tests/mcnemar_test.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 | 5b49cafe0599 |
| children | 1c89599167a6 |
| rev | line source |
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14138
72c96de7a403
maint: update copyright notices for 2012
John W. Eaton <jwe@octave.org>
parents:
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diff
changeset
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1 ## Copyright (C) 1996-2012 Kurt Hornik |
| 3426 | 2 ## |
| 3922 | 3 ## This file is part of Octave. |
| 4 ## | |
| 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 | |
| 7016 | 7 ## the Free Software Foundation; either version 3 of the License, or (at |
| 8 ## your option) any later version. | |
| 3426 | 9 ## |
| 3922 | 10 ## Octave is distributed in the hope that it will be useful, but |
| 3200 | 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 3426 | 13 ## General Public License for more details. |
| 14 ## | |
| 3200 | 15 ## You should have received a copy of the GNU General Public License |
| 7016 | 16 ## along with Octave; see the file COPYING. If not, see |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 3200 | 18 |
| 3454 | 19 ## -*- texinfo -*- |
| 20 ## @deftypefn {Function File} {[@var{pval}, @var{chisq}, @var{df}] =} mcnemar_test (@var{x}) | |
| 21 ## For a square contingency table @var{x} of data cross-classified on | |
| 22 ## the row and column variables, McNemar's test can be used for testing | |
| 23 ## the null hypothesis of symmetry of the classification probabilities. | |
| 3200 | 24 ## |
| 3454 | 25 ## Under the null, @var{chisq} is approximately distributed as chisquare |
| 26 ## with @var{df} degrees of freedom. | |
| 3200 | 27 ## |
| 3454 | 28 ## The p-value (1 minus the CDF of this distribution at @var{chisq}) is |
| 29 ## returned in @var{pval}. | |
| 3200 | 30 ## |
| 31 ## If no output argument is given, the p-value of the test is displayed. | |
| 3454 | 32 ## @end deftypefn |
| 3426 | 33 |
| 5428 | 34 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> |
| 3456 | 35 ## Description: McNemar's test for symmetry |
| 3426 | 36 |
| 3200 | 37 function [pval, chisq, df] = mcnemar_test (x) |
| 3426 | 38 |
| 3200 | 39 if (nargin != 1) |
| 6046 | 40 print_usage (); |
| 3200 | 41 endif |
| 3426 | 42 |
| 4030 | 43 if (! (min (size (x)) > 1) && issquare (x)) |
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44 error ("mcnemar_test: X must be a square matrix of size > 1"); |
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45 elseif (! (all (all (x >= 0)) && all (all (x == fix (x))))) |
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Rik <octave@nomad.inbox5.com>
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46 error ("mcnemar_test: all entries of X must be non-negative integers"); |
| 3200 | 47 endif |
| 3426 | 48 |
| 3200 | 49 r = rows (x); |
| 50 df = r * (r - 1) / 2; | |
| 51 if (r == 2) | |
| 52 num = max (abs (x - x') - 1, 0) .^ 2; | |
| 53 else | |
| 54 num = abs (x - x') .^ 2; | |
| 55 endif | |
| 3426 | 56 |
| 3200 | 57 chisq = sum (sum (triu (num ./ (x + x'), 1))); |
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Rik <octave@nomad.inbox5.com>
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58 pval = 1 - chi2cdf (chisq, df); |
| 3426 | 59 |
| 3200 | 60 if (nargout == 0) |
| 3456 | 61 printf (" pval: %g\n", pval); |
| 3200 | 62 endif |
| 3426 | 63 |
| 3200 | 64 endfunction |
| 65 | |
| 66 | |
| 3426 | 67 |