Mercurial > octave
view scripts/general/subsindex.m @ 23084:ef4d915df748
maint: Merge stable to default.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Mon, 23 Jan 2017 14:27:48 -0500 |
parents | 3a2b891d0b33 e9a0469dedd9 |
children | 092078913d54 |
line wrap: on
line source
## Copyright (C) 2008-2016 David Bateman ## ## 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 {} {@var{idx} =} subsindex (@var{obj}) ## Convert an object to an index vector. ## ## When @var{obj} is a class object defined with a class constructor, then ## @code{subsindex} is the overloading method that allows the conversion of ## this class object to a valid indexing vector. It is important to note that ## @code{subsindex} must return a zero-based real integer vector of the class ## @qcode{"double"}. For example, if the class constructor were ## ## @example ## @group ## function obj = myclass (a) ## obj = class (struct ("a", a), "myclass"); ## endfunction ## @end group ## @end example ## ## @noindent ## then the @code{subsindex} function ## ## @example ## @group ## function idx = subsindex (obj) ## idx = double (obj.a) - 1.0; ## endfunction ## @end group ## @end example ## ## @noindent ## could be used as follows ## ## @example ## @group ## a = myclass (1:4); ## b = 1:10; ## b(a) ## @result{} 1 2 3 4 ## @end group ## @end example ## ## @seealso{class, subsref, subsasgn} ## @end deftypefn function idx = subsindex (obj) if (nargin != 1) print_usage (); endif ## Only way to get here is if subsindex has not been overloaded by a class. error ('subsindex: not defined for class "%s"', class (obj)); endfunction %!error <not defined for class "double"> subsindex (1) ## Test input validation %!error subsindex () %!error subsindex (1, 2)