Mercurial > octave
view scripts/statistics/corr.m @ 30920:47cbc69e66cd
eliminate direct access to call stack from evaluator
The call stack is an internal implementation detail of the evaluator.
Direct access to it outside of the evlauator should not be needed.
* pt-eval.h (tree_evaluator::get_call_stack): Delete.
author | John W. Eaton <jwe@octave.org> |
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date | Fri, 08 Apr 2022 15:19:22 -0400 |
parents | 5d3faba0342e |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 1996-2022 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{r} =} corr (@var{x}) ## @deftypefnx {} {@var{r} =} corr (@var{x}, @var{y}) ## Compute matrix of correlation coefficients. ## ## If each row of @var{x} and @var{y} is an observation and each column is ## a variable, then the @w{(@var{i}, @var{j})-th} entry of ## @code{corr (@var{x}, @var{y})} is the correlation between the ## @var{i}-th variable in @var{x} and the @var{j}-th variable in @var{y}. ## @tex ## $$ ## {\rm corr}(x,y) = {{\rm cov}(x,y) \over {\rm std}(x) \, {\rm std}(y)} ## $$ ## @end tex ## @ifnottex ## ## @example ## corr (@var{x},@var{y}) = cov (@var{x},@var{y}) / (std (@var{x}) * std (@var{y})) ## @end example ## ## @end ifnottex ## If called with one argument, compute @code{corr (@var{x}, @var{x})}, ## the correlation between the columns of @var{x}. ## @seealso{cov} ## @end deftypefn function r = corr (x, y = []) if (nargin < 1) print_usage (); endif ## Input validation is done by cov.m. Don't repeat tests here ## Special case, scalar is always 100% correlated with itself if (isscalar (x)) if (isa (x, "single")) r = single (1); else r = 1; endif return; endif ## No check for division by zero error, which happens only when ## there is a constant vector and should be rare. if (nargin == 2) c = cov (x, y); s = std (x)' * std (y); r = c ./ s; else c = cov (x); s = sqrt (diag (c)); r = c ./ (s * s'); endif endfunction %!test %! x = rand (10); %! cc1 = corr (x); %! cc2 = corr (x, x); %! assert (size (cc1) == [10, 10] && size (cc2) == [10, 10]); %! assert (cc1, cc2, sqrt (eps)); %!test %! x = [1:3]'; %! y = [3:-1:1]'; %! assert (corr (x, y), -1, 5*eps); %! assert (corr (x, flipud (y)), 1, 5*eps); %! assert (corr ([x, y]), [1 -1; -1 1], 5*eps); %!test %! x = single ([1:3]'); %! y = single ([3:-1:1]'); %! assert (corr (x, y), single (-1), 5*eps); %! assert (corr (x, flipud (y)), single (1), 5*eps); %! assert (corr ([x, y]), single ([1 -1; -1 1]), 5*eps); %!assert (corr (5), 1) %!assert (corr (single (5)), single (1)) ## Test input validation %!error <Invalid call> corr () %!error corr ([1; 2], ["A", "B"]) %!error corr (ones (2,2,2)) %!error corr (ones (2,2), ones (2,2,2))