Mercurial > octave
view scripts/general/logspace.m @ 30893:e1788b1a315f
maint: Use "fcn" as preferred abbreviation for "function" in m-files.
* accumarray.m, accumdim.m, quadl.m, quadv.m, randi.m, structfun.m,
__is_function__.m, uigetfile.m, uimenu.m, uiputfile.m, doc_cache_create.m,
colorspace_conversion_input_check.m, imageIO.m, argnames.m, vectorize.m,
vectorize.m, normest1.m, inputname.m, nthargout.m, display_info_file.m,
decic.m, ode15i.m, ode15s.m, ode23.m, ode23s.m, ode45.m, odeset.m,
check_default_input.m, integrate_adaptive.m, ode_event_handler.m,
runge_kutta_23.m, runge_kutta_23s.m, runge_kutta_45_dorpri.m,
runge_kutta_interpolate.m, starting_stepsize.m, __all_opts__.m, fminbnd.m,
fminsearch.m, fminunc.m, fsolve.m, fzero.m, sqp.m, fplot.m, plotyy.m,
__bar__.m, __ezplot__.m, flat_entry.html, profexport.m, movfun.m, bicg.m,
bicgstab.m, cgs.m, eigs.m, gmres.m, pcg.m, __alltohandles__.m, __sprand__.m,
qmr.m, tfqmr.m, dump_demos.m:
Replace "func", "fun", "fn" in documentation and variable names with "fcn".
author | Rik <rik@octave.org> |
---|---|
date | Mon, 04 Apr 2022 18:14:56 -0700 |
parents | 5d3faba0342e |
children | 5d6b058a22dc |
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######################################################################## ## ## Copyright (C) 1993-2022 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{y} =} logspace (@var{a}, @var{b}) ## @deftypefnx {} {@var{y} =} logspace (@var{a}, @var{b}, @var{n}) ## @deftypefnx {} {@var{y} =} logspace (@var{a}, pi, @var{n}) ## Return a row vector with @var{n} elements logarithmically spaced from ## @tex ## $10^{a}$ to $10^{b}$. ## @end tex ## @ifnottex ## 10^@var{a} to 10^@var{b}. ## @end ifnottex ## ## If @var{n} is unspecified it defaults to 50. ## ## If @var{b} is equal to ## @tex ## $\pi$, ## @end tex ## @ifnottex ## pi, ## @end ifnottex ## the points are between ## @tex ## $10^{a}$ and $\pi$, ## @end tex ## @ifnottex ## 10^@var{a} and pi, ## @end ifnottex ## @emph{not} ## @tex ## $10^{a}$ and $10^{\pi}$, ## @end tex ## @ifnottex ## 10^@var{a} and 10^pi, ## @end ifnottex ## in order to be compatible with the corresponding @sc{matlab} function. ## ## Also for compatibility with @sc{matlab}, return the right-hand side of ## the range ## @tex ## ($10^{b}$) ## @end tex ## @ifnottex ## (10^@var{b}) ## @end ifnottex ## when just a single value is requested. ## @seealso{linspace} ## @end deftypefn function y = logspace (a, b, n = 50) if (nargin < 2) print_usage (); endif if (! (isscalar (a) && isscalar (b) && isscalar (n))) error ("logspace: arguments A, B, and N must be scalars"); endif npoints = fix (n); if (b == pi) b = log10 (pi); endif y = 10 .^ (linspace (a, b, npoints)); endfunction %!test %! x1 = logspace (1, 2); %! x2 = logspace (1, 2, 10.1); %! x3 = logspace (1, -2, 10); %! x4 = logspace (1, pi, 10); %! assert (size (x1) == [1, 50]); %! assert (abs (x1(1) - 10) < eps); %! assert (abs (x1(50) - 100) < eps); %! assert (size (x2) == [1, 10]); %! assert (abs (x2(1) - 10) < eps); %! assert (abs (x2(10) - 100) < eps); %! assert (size (x3) == [1, 10]); %! assert (abs (x3(1) - 10) < eps); %! assert (abs (x3(10) - 0.01) < eps); %! assert (size (x4) == [1, 10]); %! assert (abs (x4(1) - 10) < eps); %! assert (abs (x4(10) - pi) < sqrt (eps)); ## Edge cases %!assert (logspace (Inf, Inf, 3), [Inf, Inf, Inf]) %!assert (logspace (-Inf, Inf, 3), [0, 1, Inf]) %!testif ; ! ismac () %! assert (logspace (Inf + 1i, Inf + 1i, 3), %! repmat (complex (-Inf,Inf), [1, 3])) %!testif ; ismac () <55538> %! assert (logspace (Inf + 1i, Inf + 1i, 3), %! repmat (complex (-Inf,Inf), [1, 3])) %!testif ; ! ismac () %! assert (logspace (-Inf + 1i, Inf + 1i, 3), %! [0, NaN + NaN * 1i, complex(-Inf, Inf)]) %!testif ; ismac () <55538> %! assert (logspace (-Inf + 1i, Inf + 1i, 3), %! [0, NaN + NaN * 1i, complex(-Inf, Inf)]) %!assert (logspace (0, Inf, 3), [1, Inf, Inf]) %!assert (logspace (0, -Inf, 3), [1, 0, 0]) %!assert (logspace (Inf, -Inf, 3), [Inf, 1, 0]) ## FIXME: These are bizarre corner cases for Matlab compatibility. See ## bug #56933. This is marked as "Won't Fix", but if linspace is updated at ## some point then these tests can be re-instated. ##%!assert (logspace (-Inf, 0, 3), [0, NaN, 1]) ##%!assert (logspace (Inf, 0, 3), [Inf, NaN, 1]) ## Test input validation %!error <Invalid call> logspace () %!error logspace ([1, 2; 3, 4], 5, 6) %!error logspace (1, [1, 2; 3, 4], 6) %!error logspace (1, 2, [1, 2; 3, 4])