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comparison scripts/statistics/base/quantile.m @ 18204:b29beed0e98d

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Use first non-singleton dimension for prctile, quantile (bug #40736). * prctile.m, quantile.m: Use first non-singleton dimension when DIM is unspecified. Change documentation to match new behavior. Add %!tests to validate change.
author Rik <rik@octave.org>
date Fri, 03 Jan 2014 11:58:21 -0800
parents d63878346099
children 0850b5212619
comparison
equal deleted inserted replaced
18203:adbbacce8aaf 18204:b29beed0e98d
30 ## the @var{p}(i)th quantiles of each column of @var{x}. 30 ## the @var{p}(i)th quantiles of each column of @var{x}.
31 ## 31 ##
32 ## If @var{p} is unspecified, return the quantiles for 32 ## If @var{p} is unspecified, return the quantiles for
33 ## @code{[0.00 0.25 0.50 0.75 1.00]}. 33 ## @code{[0.00 0.25 0.50 0.75 1.00]}.
34 ## The optional argument @var{dim} determines the dimension along which 34 ## The optional argument @var{dim} determines the dimension along which
35 ## the quantiles are calculated. If @var{dim} is omitted, and @var{x} is 35 ## the quantiles are calculated. If @var{dim} is omitted it defaults to
36 ## a vector or matrix, it defaults to 1 (column-wise quantiles). If 36 ## the first non-singleton dimension.
37 ## @var{x} is an N-D array, @var{dim} defaults to the first non-singleton
38 ## dimension.
39 ## 37 ##
40 ## The methods available to calculate sample quantiles are the nine methods 38 ## The methods available to calculate sample quantiles are the nine methods
41 ## used by R (@url{http://www.r-project.org/}). The default value is 39 ## used by R (@url{http://www.r-project.org/}). The default value is
42 ## @w{METHOD = 5}. 40 ## @w{METHOD = 5}.
43 ## 41 ##
106 ## @end deftypefn 104 ## @end deftypefn
107 105
108 ## Author: Ben Abbott <bpabbott@mac.com> 106 ## Author: Ben Abbott <bpabbott@mac.com>
109 ## Description: Matlab style quantile function of a discrete/continuous distribution 107 ## Description: Matlab style quantile function of a discrete/continuous distribution
110 108
111 function q = quantile (x, p = [], dim = 1, method = 5) 109 function q = quantile (x, p = [], dim, method = 5)
112 110
113 if (nargin < 1 || nargin > 4) 111 if (nargin < 1 || nargin > 4)
114 print_usage (); 112 print_usage ();
115 endif 113 endif
116 114
124 122
125 if (! (isnumeric (p) && isvector (p))) 123 if (! (isnumeric (p) && isvector (p)))
126 error ("quantile: P must be a numeric vector"); 124 error ("quantile: P must be a numeric vector");
127 endif 125 endif
128 126
129 if (!(isscalar (dim) && dim == fix (dim)) 127 if (nargin < 3)
130 || !(1 <= dim && dim <= ndims (x))) 128 ## Find the first non-singleton dimension.
131 error ("quantile: DIM must be an integer and a valid dimension"); 129 (dim = find (size (x) > 1, 1)) || (dim = 1);
130 else
131 if (!(isscalar (dim) && dim == fix (dim))
132 || !(1 <= dim && dim <= ndims (x)))
133 error ("quantile: DIM must be an integer and a valid dimension");
134 endif
132 endif 135 endif
133 136
134 ## Set the permutation vector. 137 ## Set the permutation vector.
135 perm = 1:ndims (x); 138 perm = 1:ndims (x);
136 perm(1) = dim; 139 perm(1) = dim;
154 ## Permute the 1st index back to dim. 157 ## Permute the 1st index back to dim.
155 q = ipermute (q, perm); 158 q = ipermute (q, perm);
156 159
157 endfunction 160 endfunction
158 161
162
163 %!test
164 %! p = 0.50;
165 %! q = quantile (1:4, p);
166 %! qa = 2.5;
167 %! assert (q, qa);
168 %! q = quantile (1:4, p, 1);
169 %! qa = [1, 2, 3, 4];
170 %! assert (q, qa);
171 %! q = quantile (1:4, p, 2);
172 %! qa = 2.5;
173 %! assert (q, qa);
174
175 %!test
176 %! p = [0.50 0.75];
177 %! q = quantile (1:4, p);
178 %! qa = [2.5 3.5];
179 %! assert (q, qa);
180 %! q = quantile (1:4, p, 1);
181 %! qa = [1, 2, 3, 4; 1, 2, 3, 4];
182 %! assert (q, qa);
183 %! q = quantile (1:4, p, 2);
184 %! qa = [2.5 3.5];
185 %! assert (q, qa);
159 186
160 %!test 187 %!test
161 %! p = 0.5; 188 %! p = 0.5;
162 %! x = sort (rand (11)); 189 %! x = sort (rand (11));
163 %! q = quantile (x, p); 190 %! q = quantile (x, p);