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comparison doc/interpreter/func.txi @ 19628:fe689210525c gui-release

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maint: Periodic merge of stable to gui-release.
author John W. Eaton <jwe@octave.org>
date Tue, 20 Jan 2015 10:05:42 -0500
parents 4cf930a64fad 446c46af4b42
children 0e1f5a750d00
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19624:6d75f1683ce8 19628:fe689210525c
4 @c 4 @c
5 @c Octave is free software; you can redistribute it and/or modify it 5 @c Octave is free software; you can redistribute it and/or modify it
6 @c under the terms of the GNU General Public License as published by the 6 @c under the terms of the GNU General Public License as published by the
7 @c Free Software Foundation; either version 3 of the License, or (at 7 @c Free Software Foundation; either version 3 of the License, or (at
8 @c your option) any later version. 8 @c your option) any later version.
9 @c 9 @c
10 @c Octave is distributed in the hope that it will be useful, but WITHOUT 10 @c Octave is distributed in the hope that it will be useful, but WITHOUT
11 @c ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 @c ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 @c FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 @c FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 @c for more details. 13 @c for more details.
14 @c 14 @c
15 @c You should have received a copy of the GNU General Public License 15 @c You should have received a copy of the GNU General Public License
16 @c along with Octave; see the file COPYING. If not, see 16 @c along with Octave; see the file COPYING. If not, see
17 @c <http://www.gnu.org/licenses/>. 17 @c <http://www.gnu.org/licenses/>.
18 18
19 @node Functions and Scripts 19 @node Functions and Scripts
468 468
469 @noindent 469 @noindent
470 This implementation handles any number of input arguments, but it's also 470 This implementation handles any number of input arguments, but it's also
471 a very simple solution to the problem. 471 a very simple solution to the problem.
472 472
473 A slightly more complex example of @code{varargin} is a function 473 A slightly more complex example of @code{varargin} is a function
474 @code{print_arguments} that prints all input arguments. Such a function 474 @code{print_arguments} that prints all input arguments. Such a function
475 can be defined like this 475 can be defined like this
476 476
477 @example 477 @example
478 @group 478 @group
777 addpath ("~/Octave") 777 addpath ("~/Octave")
778 @end example 778 @end example
779 779
780 @noindent 780 @noindent
781 After this the directory @samp{~/Octave} will be searched for functions. 781 After this the directory @samp{~/Octave} will be searched for functions.
782 782
783 @DOCSTRING(addpath) 783 @DOCSTRING(addpath)
784 784
785 @DOCSTRING(genpath) 785 @DOCSTRING(genpath)
786 786
787 @DOCSTRING(rmpath) 787 @DOCSTRING(rmpath)
856 @end group 856 @end group
857 @end example 857 @end example
858 858
859 @noindent 859 @noindent
860 Then if the path to @code{func1} is @code{<directory>/func1.m}, and if 860 Then if the path to @code{func1} is @code{<directory>/func1.m}, and if
861 @code{func2} is found in the directory @code{<directory>/private/func2.m}, 861 @code{func2} is found in the directory @code{<directory>/private/func2.m},
862 then @code{func2} is only available for use of the functions, like 862 then @code{func2} is only available for use of the functions, like
863 @code{func1}, that are found in @code{<directory>}. 863 @code{func1}, that are found in @code{<directory>}.
864 864
865 @node Nested Functions 865 @node Nested Functions
866 @subsection Nested Functions 866 @subsection Nested Functions
867 867
1017 @subsection Overloading and Autoloading 1017 @subsection Overloading and Autoloading
1018 1018
1019 Functions can be overloaded to work with different input arguments. For 1019 Functions can be overloaded to work with different input arguments. For
1020 example, the operator '+' has been overloaded in Octave to work with single, 1020 example, the operator '+' has been overloaded in Octave to work with single,
1021 double, uint8, int32, and many other arguments. The preferred way to overload 1021 double, uint8, int32, and many other arguments. The preferred way to overload
1022 functions is through classes and object oriented programming 1022 functions is through classes and object oriented programming
1023 (@pxref{Function Overloading}). Occasionally, however, one needs to undo 1023 (@pxref{Function Overloading}). Occasionally, however, one needs to undo
1024 user overloading and call the default function associated with a specific 1024 user overloading and call the default function associated with a specific
1025 type. The @code{builtin} function exists for this purpose. 1025 type. The @code{builtin} function exists for this purpose.
1026 1026
1027 @DOCSTRING(builtin) 1027 @DOCSTRING(builtin)
1120 @enumerate 1 1120 @enumerate 1
1121 @item Subfunction 1121 @item Subfunction
1122 A subfunction with the required function name in the given scope. 1122 A subfunction with the required function name in the given scope.
1123 1123
1124 @item Private function 1124 @item Private function
1125 A function defined within a private directory of the directory 1125 A function defined within a private directory of the directory
1126 which contains the current function. 1126 which contains the current function.
1127 1127
1128 @item Class constructor 1128 @item Class constructor
1129 A function that constuctors a user class as defined in chapter 1129 A function that constuctors a user class as defined in chapter
1130 @ref{Object Oriented Programming}. 1130 @ref{Object Oriented Programming}.
1131 1131
1132 @item Class method 1132 @item Class method
1133 An overloaded function of a class as in chapter 1133 An overloaded function of a class as in chapter
1134 @ref{Object Oriented Programming}. 1134 @ref{Object Oriented Programming}.
1166 named in a script file are not local variables, but are in the same 1166 named in a script file are not local variables, but are in the same
1167 scope as the other variables that are visible on the command line. 1167 scope as the other variables that are visible on the command line.
1168 1168
1169 Even though a script file may not begin with the @code{function} 1169 Even though a script file may not begin with the @code{function}
1170 keyword, it is possible to define more than one function in a single 1170 keyword, it is possible to define more than one function in a single
1171 script file and load (but not execute) all of them at once. To do 1171 script file and load (but not execute) all of them at once. To do
1172 this, the first token in the file (ignoring comments and other white 1172 this, the first token in the file (ignoring comments and other white
1173 space) must be something other than @code{function}. If you have no 1173 space) must be something other than @code{function}. If you have no
1174 other statements to evaluate, you can use a statement that has no 1174 other statements to evaluate, you can use a statement that has no
1175 effect, like this: 1175 effect, like this:
1176 1176
1259 @cindex anonymous functions 1259 @cindex anonymous functions
1260 @cindex inline, inline functions 1260 @cindex inline, inline functions
1261 1261
1262 It can be very convenient store a function in a variable so that it 1262 It can be very convenient store a function in a variable so that it
1263 can be passed to a different function. For example, a function that 1263 can be passed to a different function. For example, a function that
1264 performs numerical minimization needs access to the function that 1264 performs numerical minimization needs access to the function that
1265 should be minimized. 1265 should be minimized.
1266 1266
1267 @menu 1267 @menu
1268 * Function Handles:: 1268 * Function Handles::
1269 * Anonymous Functions:: 1269 * Anonymous Functions::
1412 @example 1412 @example
1413 my_command hello world 1413 my_command hello world
1414 @end example 1414 @end example
1415 1415
1416 @noindent 1416 @noindent
1417 is equivalent to 1417 is equivalent to
1418 1418
1419 @example 1419 @example
1420 my_command ("hello", "world") 1420 my_command ("hello", "world")
1421 @end example 1421 @end example
1422 1422