Mercurial > hg > octave-lyh
annotate scripts/statistics/distributions/cauchy_inv.m @ 11094:add5beb3b845
avoid use of | and & in IF conditions in statistics distribution functions
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Sat, 09 Oct 2010 11:55:51 -0400 |
| parents | 3306cfcb856e |
| children | c776f063fefe |
| rev | line source |
|---|---|
| 7017 | 1 ## Copyright (C) 1995, 1996, 1997, 1998, 2000, 2002, 2004, 2005, 2006, |
| 2 ## 2007 Kurt Hornik | |
| 3426 | 3 ## |
| 3922 | 4 ## This file is part of Octave. |
| 5 ## | |
| 6 ## Octave is free software; you can redistribute it and/or modify it | |
| 7 ## under the terms of the GNU General Public License as published by | |
| 7016 | 8 ## the Free Software Foundation; either version 3 of the License, or (at |
| 9 ## your option) any later version. | |
| 3426 | 10 ## |
| 3922 | 11 ## Octave is distributed in the hope that it will be useful, but |
| 3191 | 12 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 3426 | 14 ## General Public License for more details. |
| 15 ## | |
| 3191 | 16 ## You should have received a copy of the GNU General Public License |
| 7016 | 17 ## along with Octave; see the file COPYING. If not, see |
| 18 ## <http://www.gnu.org/licenses/>. | |
| 3191 | 19 |
| 3456 | 20 ## -*- texinfo -*- |
| 21 ## @deftypefn {Function File} {} cauchy_inv (@var{x}, @var{lambda}, @var{sigma}) | |
| 22 ## For each element of @var{x}, compute the quantile (the inverse of the | |
| 23 ## CDF) at @var{x} of the Cauchy distribution with location parameter | |
| 24 ## @var{lambda} and scale parameter @var{sigma}. Default values are | |
| 25 ## @var{lambda} = 0, @var{sigma} = 1. | |
| 26 ## @end deftypefn | |
| 3191 | 27 |
| 5428 | 28 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> |
| 3456 | 29 ## Description: Quantile function of the Cauchy distribution |
| 3191 | 30 |
| 31 function inv = cauchy_inv (x, location, scale) | |
| 3426 | 32 |
| 3456 | 33 if (! (nargin == 1 || nargin == 3)) |
| 6046 | 34 print_usage (); |
| 3191 | 35 endif |
| 3426 | 36 |
| 3191 | 37 if (nargin == 1) |
| 38 location = 0; | |
| 39 scale = 1; | |
| 40 endif | |
| 3426 | 41 |
| 4854 | 42 if (!isscalar (location) || !isscalar (scale)) |
| 43 [retval, x, location, scale] = common_size (x, location, scale); | |
| 44 if (retval > 0) | |
| 45 error ("cauchy_inv: x, lambda and sigma must be of common size or scalar"); | |
| 46 endif | |
| 3191 | 47 endif |
| 3426 | 48 |
| 4854 | 49 sz = size (x); |
|
10525
3306cfcb856e
Replace constructs like "NaN * one()" with "NaN()" and "Inf * ones ()" with "Inf()"
David Bateman <dbateman@free.fr>
parents:
7017
diff
changeset
|
50 inv = NaN (sz); |
| 3426 | 51 |
| 3191 | 52 ok = ((location > -Inf) & (location < Inf) & |
| 53 (scale > 0) & (scale < Inf)); | |
| 3426 | 54 |
| 3191 | 55 k = find ((x == 0) & ok); |
| 3456 | 56 if (any (k)) |
| 4854 | 57 inv(k) = -Inf; |
| 3191 | 58 endif |
| 3426 | 59 |
| 3191 | 60 k = find ((x > 0) & (x < 1) & ok); |
| 3456 | 61 if (any (k)) |
| 4854 | 62 if (isscalar (location) && isscalar (scale)) |
| 63 inv(k) = location - scale .* cot (pi * x(k)); | |
| 64 else | |
| 65 inv(k) = location(k) - scale(k) .* cot (pi * x(k)); | |
| 66 endif | |
| 3191 | 67 endif |
| 3426 | 68 |
| 3191 | 69 k = find ((x == 1) & ok); |
| 3456 | 70 if (any (k)) |
| 4854 | 71 inv(k) = Inf; |
| 3191 | 72 endif |
| 3426 | 73 |
| 3191 | 74 endfunction |