Mercurial > octave-nkf
view scripts/general/cart2pol.m @ 20651:e54ecb33727e
lo-array-gripes.cc: Remove FIXME's related to buffer size.
* lo-array-gripes.cc: Remove FIXME's related to buffer size. Shorten sprintf
buffers from 100 to 64 characters (still well more than 19 required).
Use 'const' decorator on constant value for clarity. Remove extra space
between variable and array bracket.
author | Rik <rik@octave.org> |
---|---|
date | Mon, 12 Oct 2015 21:13:47 -0700 |
parents | 7503499a252b |
children |
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## Copyright (C) 2000-2015 Kai Habel ## ## 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{theta}, @var{r}] =} cart2pol (@var{x}, @var{y}) ## @deftypefnx {Function File} {[@var{theta}, @var{r}, @var{z}] =} cart2pol (@var{x}, @var{y}, @var{z}) ## @deftypefnx {Function File} {[@var{theta}, @var{r}] =} cart2pol (@var{C}) ## @deftypefnx {Function File} {[@var{theta}, @var{r}, @var{z}] =} cart2pol (@var{C}) ## @deftypefnx {Function File} {@var{P} =} cart2pol (@dots{}) ## ## Transform Cartesian coordinates to polar or cylindrical coordinates. ## ## The inputs @var{x}, @var{y} (, and @var{z}) must be the same shape, or ## scalar. If called with a single matrix argument then each row of @var{C} ## represents the Cartesian coordinate (@var{x}, @var{y} (, @var{z})). ## ## @var{theta} describes the angle relative to the positive x-axis. ## ## @var{r} is the distance to the z-axis @w{(0, 0, z)}. ## ## If only a single return argument is requested then return a matrix @var{P} ## where each row represents one polar/(cylindrical) coordinate ## (@var{theta}, @var{phi} (, @var{z})). ## @seealso{pol2cart, cart2sph, sph2cart} ## @end deftypefn ## Author: Kai Habel <kai.habel@gmx.de> ## Adapted-by: jwe function [theta, r, z] = cart2pol (x, y, z = []) if (nargin < 1 || nargin > 3) print_usage (); endif if (nargin == 1) if (ismatrix (x) && (columns (x) == 2 || columns (x) == 3)) if (columns (x) == 3) z = x(:,3); endif y = x(:,2); x = x(:,1); else error ("cart2pol: matrix input must have 2 or 3 columns [X, Y (, Z)]"); endif elseif (nargin == 2) if (! ((ismatrix (x) && ismatrix (y)) && (size_equal (x, y) || isscalar (x) || isscalar (y)))) error ("cart2pol: arguments must be matrices of same size, or scalar"); endif elseif (nargin == 3) if (! ((ismatrix (x) && ismatrix (y) && ismatrix (z)) && (size_equal (x, y) || isscalar (x) || isscalar (y)) && (size_equal (x, z) || isscalar (x) || isscalar (z)) && (size_equal (y, z) || isscalar (y) || isscalar (z)))) error ("cart2pol: arguments must be matrices of same size, or scalar"); endif endif theta = atan2 (y, x); r = sqrt (x .^ 2 + y .^ 2); if (nargout <= 1) theta = [theta(:), r(:), z(:)]; endif endfunction %!test %! x = [0, 1, 2]; %! y = 0; %! [t, r] = cart2pol (x, y); %! assert (t, [0, 0, 0]); %! assert (r, x); %!test %! x = [0, 1, 2]; %! y = [0, 1, 2]; %! P = cart2pol (x, y); %! assert (P(:,1), [0; pi/4; pi/4], sqrt (eps)); %! assert (P(:,2), sqrt (2)*[0; 1; 2], sqrt (eps)); %!test %! x = [0, 1, 2]; %! y = [0, 1, 2]; %! z = [0, 1, 2]; %! [t, r, z2] = cart2pol (x, y, z); %! assert (t, [0, pi/4, pi/4], sqrt (eps)); %! assert (r, sqrt (2)*[0, 1, 2], sqrt (eps)); %! assert (z, z2); %!test %! x = [0, 1, 2]; %! y = 0; %! z = 0; %! [t, r, z2] = cart2pol (x, y, z); %! assert (t, [0, 0, 0], eps); %! assert (r, x, eps); %! assert (z, z2); %!test %! x = 0; %! y = [0, 1, 2]; %! z = 0; %! [t, r, z2] = cart2pol (x, y, z); %! assert (t, [0, 1, 1]*pi/2, eps); %! assert (r, y, eps); %! assert (z, z2); %!test %! x = 0; %! y = 0; %! z = [0, 1, 2]; %! [t, r, z2] = cart2pol (x, y, z); %! assert (t, 0); %! assert (r, 0); %! assert (z, z2); %!test %! C = [0, 0; 1, 1; 2, 2]; %! P = [0, 0; pi/4, sqrt(2); pi/4, 2*sqrt(2)]; %! assert (cart2pol (C), P, sqrt (eps)); %!test %! C = [0, 0, 0; 1, 1, 1; 2, 2, 2]; %! P = [0, 0, 0; pi/4, sqrt(2), 1; pi/4, 2*sqrt(2), 2]; %! assert (cart2pol (C), P, sqrt (eps));