Mercurial > octave-nkf
view scripts/statistics/tests/t_test.m @ 20216:aa36fb998a4d stable
maint: Remove unnecessary whitespace at end of lines.
* libgui/Makefile.am, libgui/graphics/Canvas.cc,
libgui/graphics/EditControl.cc, libgui/graphics/Figure.cc,
libgui/graphics/MouseModeActionGroup.cc, libgui/graphics/annotation-dialog.cc,
libgui/graphics/annotation-dialog.h, libgui/graphics/gl-select.cc,
libgui/graphics/module.mk, libgui/kb-layouts/default.keytab,
libgui/kb-layouts/linux.keytab, libgui/kb-layouts/vt420pc.keytab,
libgui/src/m-editor/find-dialog.cc, libgui/src/main-window.cc,
libgui/src/octave-qt-link.cc, libgui/src/octave-qt-link.h,
libgui/src/shortcut-manager.h, libinterp/corefcn/error.cc,
libinterp/corefcn/find.cc, libinterp/corefcn/gl2ps-renderer.cc,
libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h,
libinterp/corefcn/octave-link.cc, libinterp/corefcn/quadcc.cc,
libinterp/corefcn/strfns.cc, libinterp/corefcn/syscalls.cc,
libinterp/corefcn/sysdep.cc, libinterp/corefcn/urlwrite.cc,
libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc,
libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/ccolamd.cc,
libinterp/dldfcn/colamd.cc, libinterp/octave-value/ov-bool-sparse.cc,
libinterp/octave-value/ov-classdef.cc, libinterp/octave-value/ov-re-sparse.cc,
libinterp/octave-value/ov-struct.cc, libinterp/parse-tree/pt-arg-list.cc,
scripts/audio/@audiorecorder/play.m, scripts/audio/wavwrite.m,
scripts/general/cart2sph.m, scripts/geometry/inpolygon.m,
scripts/gui/listdlg.m, scripts/gui/msgbox.m,
scripts/gui/private/message_dialog.m, scripts/help/get_first_help_sentence.m,
scripts/help/lookfor.m, scripts/image/imshow.m, scripts/io/strread.m,
scripts/java/javamem.m, scripts/miscellaneous/dir.m,
scripts/miscellaneous/edit.m, scripts/miscellaneous/genvarname.m,
scripts/miscellaneous/gzip.m, scripts/miscellaneous/private/__w2mpth__.m,
scripts/plot/appearance/annotation.m, scripts/plot/draw/colorbar.m,
scripts/plot/draw/quiver3.m, scripts/plot/util/hold.m,
scripts/plot/util/print.m, scripts/polynomial/mkpp.m,
scripts/polynomial/polyder.m, scripts/polynomial/spline.m,
scripts/polynomial/unmkpp.m, scripts/signal/arma_rnd.m, scripts/sparse/gplot.m,
scripts/statistics/tests/t_test.m,
scripts/statistics/tests/t_test_regression.m, scripts/strings/mat2str.m,
scripts/strings/strsplit.m, scripts/strings/strtrunc.m,
scripts/strings/untabify.m, scripts/testfun/assert.m:
maint: Remove unnecessary whitespace at end of lines.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 12 May 2015 09:22:01 -0700 |
parents | d9341b422488 |
children |
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## Copyright (C) 1995-2015 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} {[@var{pval}, @var{t}, @var{df}] =} t_test (@var{x}, @var{m}, @var{alt}) ## For a sample @var{x} from a normal distribution with unknown mean and ## variance, perform a t-test of the null hypothesis ## @code{mean (@var{x}) == @var{m}}. ## ## Under the null, the test statistic @var{t} follows a Student distribution ## with @code{@var{df} = length (@var{x}) - 1} degrees of freedom. ## ## With the optional argument string @var{alt}, the alternative of interest ## can be selected. If @var{alt} is @qcode{"!="} or @qcode{"<>"}, the null ## is tested against the two-sided alternative @code{mean (@var{x}) != ## @var{m}}. If @var{alt} is @qcode{">"}, the one-sided alternative ## @code{mean (@var{x}) > @var{m}} is considered. Similarly for @var{"<"}, ## the one-sided alternative @code{mean (@var{x}) < @var{m}} is considered. ## The default is the two-sided case. ## ## The p-value of the test is returned in @var{pval}. ## ## If no output argument is given, the p-value of the test is displayed. ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Description: Student's one-sample t test function [pval, t, df] = t_test (x, m, alt) if (nargin < 2 || nargin > 3) print_usage (); endif if (! isvector (x)) error ("t_test: X must be a vector"); endif if (! isscalar (m)) error ("t_test: M must be a scalar"); endif n = length (x); df = n - 1; t = sqrt (n) * (sum (x) / n - m) / std (x); cdf = tcdf (t, df); if (nargin == 2) alt = "!="; endif if (! ischar (alt)) error ("t_test: ALT must be a string"); endif if (strcmp (alt, "!=") || strcmp (alt, "<>")) pval = 2 * min (cdf, 1 - cdf); elseif (strcmp (alt, ">")) pval = 1 - cdf; elseif (strcmp (alt, "<")) pval = cdf; else error ("t_test: option %s not recognized", alt); endif if (nargout == 0) printf (" pval: %g\n", pval); endif endfunction %!test %! ## Two-sided (also the default option) %! x = rand (10,1); n = length (x); %! u0 = 0.5; # true mean %! xbar = mean (x); %! pval = t_test (x, u0, "!="); %! if (xbar >= u0) %! tval = abs (tinv (0.5*pval, n-1)); %! else %! tval = -abs (tinv (0.5*pval, n-1)); %! endif %! unew = tval * std(x)/sqrt(n) + u0; %! assert (xbar, unew, 100*eps); %!test %! x = rand (10,1); n = length (x); %! u0 = 0.5; %! pval = t_test (x, u0, ">"); %! tval = tinv (1-pval, n-1); %! unew = tval * std(x)/sqrt(n) + u0; %! assert (mean (x), unew, 100*eps); %!test %! x = rand (10,1); n = length (x); %! u0 = 0.5; %! pval = t_test (x, u0, "<"); %! tval = tinv (pval, n-1); %! unew = tval * std(x)/sqrt(n) + u0; %! assert (mean (x), unew, 100*eps);