update packages

[CreaPhase.git] / octave_packages / m / statistics / base / statistics.m

diff --git a/octave_packages/m/statistics/base/statistics.m b/octave_packages/m/statistics/base/statistics.m
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+## Copyright (C) 1995-2012 Kurt Hornik
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Function File} {} statistics (@var{x})
+## @deftypefnx {Function File} {} statistics (@var{x}, @var{dim})
+## Return a vector with the minimum, first quartile, median, third quartile,
+## maximum, mean, standard deviation, skewness, and kurtosis of the elements of
+## the vector @var{x}.
+##
+## If @var{x} is a matrix, calculate statistics over the first
+## non-singleton dimension.
+## If the optional argument @var{dim} is given, operate along this dimension.
+## @seealso{min, max, median, mean, std, skewness, kurtosis}
+## @end deftypefn
+
+## Author: KH <Kurt.Hornik@wu-wien.ac.at>
+## Description: Compute basic statistics
+
+function stats = statistics (x, dim)
+
+  if (nargin != 1 && nargin != 2)
+    print_usage ();
+  endif
+
+  if (! (isnumeric (x) || islogical (x)))
+    error ("statistics: X must be a numeric vector or matrix");
+  endif
+
+  nd = ndims (x);
+  sz = size (x);
+  if (nargin != 2)
+    ## Find the first non-singleton dimension.
+    (dim = find (sz > 1, 1)) || (dim = 1);
+  else
+    if (!(isscalar (dim) && dim == fix (dim))
+        || !(1 <= dim && dim <= nd))
+      error ("statistics: DIM must be an integer and a valid dimension");
+    endif
+  endif
+
+  if (sz(dim) < 2)
+    error ("statistics: dimension of X is too small (<2)");
+  endif
+
+  emp_inv = quantile (x, [0.25; 0.5; 0.75], dim, 7);
+
+  stats = cat (dim, min (x, [], dim), emp_inv, max (x, [], dim), mean (x, dim),
+               std (x, [], dim), skewness (x, dim), kurtosis (x, dim));
+
+endfunction
+
+
+%!test
+%! x = rand (7,5);
+%! s = statistics (x);
+%! assert (min (x), s(1,:), eps);
+%! assert (median (x), s(3,:), eps);
+%! assert (max (x), s(5,:), eps);
+%! assert (mean (x), s(6,:), eps);
+%! assert (std (x), s(7,:), eps);
+%! assert (skewness (x), s(8,:), eps);
+%! assert (kurtosis (x), s(9,:), eps);
+
+%% Test input validation
+%!error statistics ()
+%!error statistics (1, 2, 3)
+%!error statistics (['A'; 'B'])
+%!error statistics (1, ones(2,2))
+%!error statistics (1, 1.5)
+%!error statistics (1, 0)
+%!error statistics (1, 3)
+%!error statistics (1)
+