update packages

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

diff --git a/octave_packages/m/statistics/base/prctile.m b/octave_packages/m/statistics/base/prctile.m
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+## Copyright (C) 2008-2012 Ben Abbott
+##
+## 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} {@var{q} =} prctile (@var{x})
+## @deftypefnx {Function File} {@var{q} =} prctile (@var{x}, @var{p})
+## @deftypefnx {Function File} {@var{q} =} prctile (@var{x}, @var{p}, @var{dim})
+## For a sample @var{x}, compute the quantiles, @var{q}, corresponding
+## to the cumulative probability values, @var{p}, in percent.  All non-numeric
+## values (NaNs) of @var{x} are ignored.
+##
+## If @var{x} is a matrix, compute the percentiles for each column and
+## return them in a matrix, such that the i-th row of @var{y} contains the
+## @var{p}(i)th percentiles of each column of @var{x}.
+##
+## If @var{p} is unspecified, return the quantiles for @code{[0 25 50 75 100]}.
+## The optional argument @var{dim} determines the dimension along which
+## the percentiles are calculated.  If @var{dim} is omitted, and @var{x} is
+## a vector or matrix, it defaults to 1 (column-wise quantiles).  When
+## @var{x} is an N-D array, @var{dim} defaults to the first non-singleton
+## dimension.
+## @seealso{quantile}
+## @end deftypefn
+
+## Author: Ben Abbott <bpabbott@mac.com>
+## Description: Matlab style prctile function.
+
+function q = prctile (x, p = [], dim)
+
+  if (nargin < 1 || nargin > 3)
+    print_usage ();
+  endif
+
+  if (! (isnumeric (x) || islogical (x)))
+    error ("prctile: X must be a numeric vector or matrix");
+  endif
+
+  if (isempty (p))
+    p = [0, 25, 50, 75, 100];
+  endif
+
+  if (! (isnumeric (p) && isvector (p)))
+    error ("prctile: P must be a numeric vector");
+  endif
+
+  nd = ndims (x);
+  if (nargin == 2)
+    if (nd == 2)
+      ## If a matrix or vector, always use 1st dimension.
+      dim = 1;
+    else
+      ## If an N-d array, find the first non-singleton dimension.
+      (dim = find (sz > 1, 1)) || (dim = 1);
+    endif
+  else
+    if (!(isscalar (dim) && dim == fix (dim))
+        || !(1 <= dim && dim <= nd))
+      error ("prctile: DIM must be an integer and a valid dimension");
+    endif
+  endif
+
+  ## Convert from percent to decimal.
+  p /= 100;
+
+  q = quantile (x, p, dim);
+
+endfunction
+
+
+%!test
+%! pct = 50;
+%! q = prctile (1:4, pct, 1);
+%! qa = [1, 2, 3, 4];
+%! assert (q, qa);
+%! q = prctile (1:4, pct, 2);
+%! qa = 2.5000;
+%! assert (q, qa);
+
+%!test
+%! pct = 50;
+%! x = [0.1126, 0.1148, 0.0521, 0.2364, 0.1393
+%!      0.1718, 0.7273, 0.2041, 0.4531, 0.1585
+%!      0.2795, 0.7978, 0.3296, 0.5567, 0.7307
+%!      0.4288, 0.8753, 0.6477, 0.6287, 0.8165
+%!      0.9331, 0.9312, 0.9635, 0.7796, 0.8461];
+%! tol = 0.0001;
+%! q = prctile (x, pct, 1);
+%! qa = [0.2795, 0.7978, 0.3296, 0.5567, 0.7307];
+%! assert (q, qa, tol);
+%! q = prctile (x, pct, 2);
+%! qa = [0.1148; 0.2041; 0.5567; 0.6477; 0.9312];
+%! assert (q, qa, tol);
+
+%!test
+%! pct = 50;
+%! tol = 0.0001;
+%! x = [0.1126, 0.1148, 0.0521, 0.2364, 0.1393
+%!      0.1718, 0.7273, 0.2041, 0.4531, 0.1585
+%!      0.2795, 0.7978, 0.3296, 0.5567, 0.7307
+%!      0.4288, 0.8753, 0.6477, 0.6287, 0.8165
+%!      0.9331, 0.9312, 0.9635, 0.7796, 0.8461];
+%! x(5,5) = Inf;
+%! q = prctile (x, pct, 1);
+%! qa = [0.2795, 0.7978, 0.3296, 0.5567, 0.7307];
+%! assert (q, qa, tol);
+%! x(5,5) = -Inf;
+%! q = prctile (x, pct, 1);
+%! qa = [0.2795, 0.7978, 0.3296, 0.5567, 0.1585];
+%! assert (q, qa, tol);
+%! x(1,1) = Inf;
+%! q = prctile (x, pct, 1);
+%! qa = [0.4288, 0.7978, 0.3296, 0.5567, 0.1585];
+%! assert (q, qa, tol);
+
+%!test
+%! pct = 50;
+%! tol = 0.0001;
+%! x = [0.1126, 0.1148, 0.0521, 0.2364, 0.1393
+%!      0.1718, 0.7273, 0.2041, 0.4531, 0.1585
+%!      0.2795, 0.7978, 0.3296, 0.5567, 0.7307
+%!      0.4288, 0.8753, 0.6477, 0.6287, 0.8165
+%!      0.9331, 0.9312, 0.9635, 0.7796, 0.8461];
+%! x(3,3) = Inf;
+%! q = prctile (x, pct, 1);
+%! qa = [0.2795, 0.7978, 0.6477, 0.5567, 0.7307];
+%! assert (q, qa, tol);
+%! q = prctile (x, pct, 2);
+%! qa = [0.1148; 0.2041; 0.7307; 0.6477; 0.9312];
+%! assert (q, qa, tol);
+
+%!test
+%! pct = 50;
+%! tol = 0.0001;
+%! x = [0.1126, 0.1148, 0.0521, 0.2364, 0.1393
+%!      0.1718, 0.7273, 0.2041, 0.4531, 0.1585
+%!      0.2795, 0.7978, 0.3296, 0.5567, 0.7307
+%!      0.4288, 0.8753, 0.6477, 0.6287, 0.8165
+%!      0.9331, 0.9312, 0.9635, 0.7796, 0.8461];
+%! x(5,5) = NaN;
+%! q = prctile (x, pct, 2);
+%! qa = [0.1148; 0.2041; 0.5567; 0.6477; 0.9322];
+%! assert (q, qa, tol);
+%! x(1,1) = NaN;
+%! q = prctile (x, pct, 2);
+%! qa = [0.1270; 0.2041; 0.5567; 0.6477; 0.9322];
+%! assert (q, qa, tol);
+%! x(3,3) = NaN;
+%! q = prctile (x, pct, 2);
+%! qa = [0.1270; 0.2041; 0.6437; 0.6477; 0.9322];
+%! assert (q, qa, tol);
+
+%% Test input validation
+%!error prctile ()
+%!error prctile (1, 2, 3, 4)
+%!error prctile (['A'; 'B'], 10)
+%!error prctile (1:10, [true, false])
+%!error prctile (1:10, ones (2,2))
+%!error prctile (1, 1, 1.5)
+%!error prctile (1, 1, 0)
+%!error prctile (1, 1, 3)