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annotate scripts/statistics/distributions/stdnormal_pdf.m @ 3922:38c61cbf086c

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[project @ 2002-05-01 06:48:35 by jwe]
author jwe
date Wed, 01 May 2002 06:48:36 +0000
parents e031284eea27
children 4b0f3b055331
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1 ## Copyright (C) 1995, 1996, 1997 Kurt Hornik
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2 ##
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3 ## This file is part of Octave.
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4 ##
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5 ## Octave is free software; you can redistribute it and/or modify it
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6 ## under the terms of the GNU General Public License as published by
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7 ## the Free Software Foundation; either version 2, or (at your option)
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8 ## any later version.
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9 ##
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10 ## Octave is distributed in the hope that it will be useful, but
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11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
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12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 ## General Public License for more details.
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14 ##
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15 ## You should have received a copy of the GNU General Public License
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16 ## along with Octave; see the file COPYING. If not, write to the Free
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17 ## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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18 ## 02111-1307, USA.
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19
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20 ## -*- texinfo -*-
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21 ## @deftypefn {Function File} {} stdnormal_pdf (@var{x})
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22 ## For each element of @var{x}, compute the probability density function
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23 ## (PDF) of the standard normal distribution at @var{x}.
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24 ## @end deftypefn
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25
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26 ## Author: TT <Teresa.Twaroch@ci.tuwien.ac.at>
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27 ## Description: PDF of the standard normal distribution
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28
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29 function pdf = stdnormal_pdf (x)
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30
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31 if (nargin != 1)
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32 usage ("stdnormal_pdf (x)");
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33 endif
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34
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35 [r, c] = size (x);
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36 s = r * c;
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37 x = reshape (x, 1, s);
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38 pdf = zeros (1, s);
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39
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40 k = find (isnan (x));
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41 if (any (k))
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42 pdf(k) = NaN * ones (1, length (k));
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43 endif
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44
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45 k = find (!isinf (x));
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46 if (any (k))
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47 pdf (k) = (2 * pi)^(- 1/2) * exp (- x(k) .^ 2 / 2);
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48 endif
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49
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50 pdf = reshape (pdf, r, c);
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51
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52 endfunction