Mercurial > octave-nkf
annotate doc/interpreter/func.txi @ 14442:c1f9b54350f9
doc: improve description of functions and scripts
* func.txi: Enumerate all the ways that functions can be defined.
| author | Doug Stewart <doug.dastew@gmail.com> |
|---|---|
| date | Fri, 24 Feb 2012 20:42:29 -0500 |
| parents | 3972c4caa60a |
| children | 460a3c6d8bf1 |
| rev | line source |
|---|---|
|
14138
72c96de7a403
maint: update copyright notices for 2012
John W. Eaton <jwe@octave.org>
parents:
14133
diff
changeset
|
1 @c Copyright (C) 1996-2012 John W. Eaton |
| 7018 | 2 @c |
| 3 @c This file is part of Octave. | |
| 4 @c | |
| 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 | |
| 7 @c Free Software Foundation; either version 3 of the License, or (at | |
| 8 @c your option) any later version. | |
| 9 @c | |
| 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 | |
| 12 @c FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 13 @c for more details. | |
| 14 @c | |
| 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 | |
| 17 @c <http://www.gnu.org/licenses/>. | |
| 3294 | 18 |
| 4167 | 19 @node Functions and Scripts |
|
9032
349616d9c38e
Cleanup top-level documentation menu in octave.texi
Rik <rdrider0-list@yahoo.com>
parents:
8920
diff
changeset
|
20 @chapter Functions and Scripts |
| 3294 | 21 @cindex defining functions |
| 22 @cindex user-defined functions | |
| 23 @cindex functions, user-defined | |
| 24 @cindex script files | |
| 25 | |
| 26 Complicated Octave programs can often be simplified by defining | |
| 27 functions. Functions can be defined directly on the command line during | |
| 28 interactive Octave sessions, or in external files, and can be called just | |
| 29 like built-in functions. | |
| 30 | |
| 31 @menu | |
|
14442
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
32 * Introduction to Function and Script Files:: |
| 3294 | 33 * Defining Functions:: |
| 34 * Multiple Return Values:: | |
| 35 * Variable-length Argument Lists:: | |
|
10209
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
36 * Ignoring Arguments:: |
| 3294 | 37 * Variable-length Return Lists:: |
|
11255
d682cd6669ac
Update info-based documentation menus to include new nodes.
Rik <octave@nomad.inbox5.com>
parents:
10828
diff
changeset
|
38 * Returning from a Function:: |
| 6510 | 39 * Default Arguments:: |
| 3294 | 40 * Function Files:: |
| 41 * Script Files:: | |
| 6638 | 42 * Function Handles Inline Functions and Anonymous Functions:: |
| 6549 | 43 * Commands:: |
| 3294 | 44 * Organization of Functions:: |
| 45 @end menu | |
| 46 | |
|
14442
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
47 @node Introduction to Function and Script Files |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
48 @section Introduction to Function and Script Files |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
49 |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
50 There are six different things covered in this section. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
51 @enumerate |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
52 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
53 Typing in a function at the command prompt. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
54 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
55 Storing a group of commands in a file - called a script file. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
56 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
57 Storing a function in a file - called a function file. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
58 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
59 Sub-functions in function files. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
60 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
61 Multiple functions in one script file. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
62 @item |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
63 Private functions. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
64 @end enumerate |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
65 |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
66 Both function files and script files end with an extension of .m, for |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
67 @sc{Matlab} compatibility. If you want more than one independent |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
68 functions in a file, it must be a script file (@pxref{Script Files}), |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
69 and to use these functions you must execute the script file before you |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
70 can use the functions that are in the script file. |
|
c1f9b54350f9
doc: improve description of functions and scripts
Doug Stewart <doug.dastew@gmail.com>
parents:
14175
diff
changeset
|
71 |
| 4167 | 72 @node Defining Functions |
| 3294 | 73 @section Defining Functions |
| 74 @cindex @code{function} statement | |
| 75 @cindex @code{endfunction} statement | |
| 76 | |
| 77 In its simplest form, the definition of a function named @var{name} | |
| 78 looks like this: | |
| 79 | |
| 80 @example | |
| 81 @group | |
| 82 function @var{name} | |
| 83 @var{body} | |
| 84 endfunction | |
| 85 @end group | |
| 86 @end example | |
| 87 | |
| 88 @noindent | |
| 89 A valid function name is like a valid variable name: a sequence of | |
| 90 letters, digits and underscores, not starting with a digit. Functions | |
| 91 share the same pool of names as variables. | |
| 92 | |
| 93 The function @var{body} consists of Octave statements. It is the | |
| 94 most important part of the definition, because it says what the function | |
| 95 should actually @emph{do}. | |
| 96 | |
| 97 For example, here is a function that, when executed, will ring the bell | |
| 98 on your terminal (assuming that it is possible to do so): | |
| 99 | |
| 100 @example | |
| 101 @group | |
| 102 function wakeup | |
| 103 printf ("\a"); | |
| 104 endfunction | |
| 105 @end group | |
| 106 @end example | |
| 107 | |
| 108 The @code{printf} statement (@pxref{Input and Output}) simply tells | |
| 109 Octave to print the string @code{"\a"}. The special character @samp{\a} | |
| 110 stands for the alert character (ASCII 7). @xref{Strings}. | |
| 111 | |
| 112 Once this function is defined, you can ask Octave to evaluate it by | |
| 113 typing the name of the function. | |
| 114 | |
| 115 Normally, you will want to pass some information to the functions you | |
| 116 define. The syntax for passing parameters to a function in Octave is | |
| 117 | |
| 118 @example | |
| 119 @group | |
| 120 function @var{name} (@var{arg-list}) | |
| 121 @var{body} | |
| 122 endfunction | |
| 123 @end group | |
| 124 @end example | |
| 125 | |
| 126 @noindent | |
| 127 where @var{arg-list} is a comma-separated list of the function's | |
| 128 arguments. When the function is called, the argument names are used to | |
| 129 hold the argument values given in the call. The list of arguments may | |
| 130 be empty, in which case this form is equivalent to the one shown above. | |
| 131 | |
| 132 To print a message along with ringing the bell, you might modify the | |
| 6510 | 133 @code{wakeup} to look like this: |
| 3294 | 134 |
| 135 @example | |
| 136 @group | |
| 137 function wakeup (message) | |
| 138 printf ("\a%s\n", message); | |
| 139 endfunction | |
| 140 @end group | |
| 141 @end example | |
| 142 | |
| 143 Calling this function using a statement like this | |
| 144 | |
| 145 @example | |
| 146 wakeup ("Rise and shine!"); | |
| 147 @end example | |
| 148 | |
| 149 @noindent | |
| 150 will cause Octave to ring your terminal's bell and print the message | |
| 151 @samp{Rise and shine!}, followed by a newline character (the @samp{\n} | |
| 152 in the first argument to the @code{printf} statement). | |
| 153 | |
| 154 In most cases, you will also want to get some information back from the | |
| 155 functions you define. Here is the syntax for writing a function that | |
| 156 returns a single value: | |
| 157 | |
| 158 @example | |
| 159 @group | |
| 160 function @var{ret-var} = @var{name} (@var{arg-list}) | |
| 161 @var{body} | |
| 162 endfunction | |
| 163 @end group | |
| 164 @end example | |
| 165 | |
| 166 @noindent | |
| 167 The symbol @var{ret-var} is the name of the variable that will hold the | |
| 168 value to be returned by the function. This variable must be defined | |
| 169 before the end of the function body in order for the function to return | |
| 170 a value. | |
| 171 | |
| 172 Variables used in the body of a function are local to the | |
| 173 function. Variables named in @var{arg-list} and @var{ret-var} are also | |
| 174 local to the function. @xref{Global Variables}, for information about | |
| 175 how to access global variables inside a function. | |
| 176 | |
| 177 For example, here is a function that computes the average of the | |
| 178 elements of a vector: | |
| 179 | |
| 180 @example | |
| 181 @group | |
| 182 function retval = avg (v) | |
| 183 retval = sum (v) / length (v); | |
| 184 endfunction | |
| 185 @end group | |
| 186 @end example | |
| 187 | |
| 188 If we had written @code{avg} like this instead, | |
| 189 | |
| 190 @example | |
| 191 @group | |
| 192 function retval = avg (v) | |
| 4029 | 193 if (isvector (v)) |
| 3294 | 194 retval = sum (v) / length (v); |
| 195 endif | |
| 196 endfunction | |
| 197 @end group | |
| 198 @end example | |
| 199 | |
| 200 @noindent | |
| 201 and then called the function with a matrix instead of a vector as the | |
| 202 argument, Octave would have printed an error message like this: | |
| 203 | |
| 204 @example | |
| 205 @group | |
|
8015
30629059b72d
Update the manual to reflect the changes in error output
sh@sh-laptop
parents:
7984
diff
changeset
|
206 error: value on right hand side of assignment is undefined |
| 3294 | 207 @end group |
| 208 @end example | |
| 209 | |
| 210 @noindent | |
| 211 because the body of the @code{if} statement was never executed, and | |
| 212 @code{retval} was never defined. To prevent obscure errors like this, | |
| 213 it is a good idea to always make sure that the return variables will | |
| 214 always have values, and to produce meaningful error messages when | |
| 215 problems are encountered. For example, @code{avg} could have been | |
| 216 written like this: | |
| 217 | |
| 218 @example | |
| 219 @group | |
| 220 function retval = avg (v) | |
| 221 retval = 0; | |
| 4029 | 222 if (isvector (v)) |
| 3294 | 223 retval = sum (v) / length (v); |
| 224 else | |
| 225 error ("avg: expecting vector argument"); | |
| 226 endif | |
| 227 endfunction | |
| 228 @end group | |
| 229 @end example | |
| 230 | |
| 231 There is still one additional problem with this function. What if it is | |
| 232 called without an argument? Without additional error checking, Octave | |
| 233 will probably print an error message that won't really help you track | |
| 234 down the source of the error. To allow you to catch errors like this, | |
| 235 Octave provides each function with an automatic variable called | |
| 236 @code{nargin}. Each time a function is called, @code{nargin} is | |
| 237 automatically initialized to the number of arguments that have actually | |
| 238 been passed to the function. For example, we might rewrite the | |
| 239 @code{avg} function like this: | |
| 240 | |
| 241 @example | |
| 242 @group | |
| 243 function retval = avg (v) | |
| 244 retval = 0; | |
| 245 if (nargin != 1) | |
| 246 usage ("avg (vector)"); | |
| 247 endif | |
| 4029 | 248 if (isvector (v)) |
| 3294 | 249 retval = sum (v) / length (v); |
| 250 else | |
| 251 error ("avg: expecting vector argument"); | |
| 252 endif | |
| 253 endfunction | |
| 254 @end group | |
| 255 @end example | |
| 256 | |
| 257 Although Octave does not automatically report an error if you call a | |
| 258 function with more arguments than expected, doing so probably indicates | |
| 259 that something is wrong. Octave also does not automatically report an | |
| 260 error if a function is called with too few arguments, but any attempt to | |
| 261 use a variable that has not been given a value will result in an error. | |
| 262 To avoid such problems and to provide useful messages, we check for both | |
| 263 possibilities and issue our own error message. | |
| 264 | |
| 4700 | 265 @DOCSTRING(nargin) |
| 3294 | 266 |
| 6558 | 267 @DOCSTRING(inputname) |
| 268 | |
| 3371 | 269 @DOCSTRING(silent_functions) |
| 3294 | 270 |
| 4167 | 271 @node Multiple Return Values |
| 3294 | 272 @section Multiple Return Values |
| 273 | |
| 274 Unlike many other computer languages, Octave allows you to define | |
| 275 functions that return more than one value. The syntax for defining | |
| 276 functions that return multiple values is | |
| 277 | |
| 278 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
279 @group |
| 3294 | 280 function [@var{ret-list}] = @var{name} (@var{arg-list}) |
| 281 @var{body} | |
| 282 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
283 @end group |
| 3294 | 284 @end example |
| 285 | |
| 286 @noindent | |
| 287 where @var{name}, @var{arg-list}, and @var{body} have the same meaning | |
| 288 as before, and @var{ret-list} is a comma-separated list of variable | |
| 289 names that will hold the values returned from the function. The list of | |
| 290 return values must have at least one element. If @var{ret-list} has | |
| 291 only one element, this form of the @code{function} statement is | |
| 292 equivalent to the form described in the previous section. | |
| 293 | |
| 294 Here is an example of a function that returns two values, the maximum | |
| 295 element of a vector and the index of its first occurrence in the vector. | |
| 296 | |
| 297 @example | |
| 298 @group | |
| 299 function [max, idx] = vmax (v) | |
| 300 idx = 1; | |
| 301 max = v (idx); | |
| 302 for i = 2:length (v) | |
| 303 if (v (i) > max) | |
| 304 max = v (i); | |
| 305 idx = i; | |
| 306 endif | |
| 307 endfor | |
| 308 endfunction | |
| 309 @end group | |
| 310 @end example | |
| 311 | |
| 312 In this particular case, the two values could have been returned as | |
| 313 elements of a single array, but that is not always possible or | |
| 314 convenient. The values to be returned may not have compatible | |
| 315 dimensions, and it is often desirable to give the individual return | |
| 316 values distinct names. | |
| 317 | |
|
13749
62d1f56b0be7
New nthargout function
Jordi Gutiérrez Hermoso <jordigh@octave.org>
parents:
12642
diff
changeset
|
318 It is possible to use the @code{nthargout} function to obtain only some |
|
14038
b0cdd60db5e5
doc: Grammarcheck documentation ahead of 3.6.0 release.
Rik <octave@nomad.inbox5.com>
parents:
13852
diff
changeset
|
319 of the return values or several at once in a cell array. |
|
b0cdd60db5e5
doc: Grammarcheck documentation ahead of 3.6.0 release.
Rik <octave@nomad.inbox5.com>
parents:
13852
diff
changeset
|
320 @ref{Cell Array Objects} |
|
13749
62d1f56b0be7
New nthargout function
Jordi Gutiérrez Hermoso <jordigh@octave.org>
parents:
12642
diff
changeset
|
321 |
|
62d1f56b0be7
New nthargout function
Jordi Gutiérrez Hermoso <jordigh@octave.org>
parents:
12642
diff
changeset
|
322 @DOCSTRING(nthargout) |
|
62d1f56b0be7
New nthargout function
Jordi Gutiérrez Hermoso <jordigh@octave.org>
parents:
12642
diff
changeset
|
323 |
| 3294 | 324 In addition to setting @code{nargin} each time a function is called, |
| 325 Octave also automatically initializes @code{nargout} to the number of | |
| 326 values that are expected to be returned. This allows you to write | |
| 327 functions that behave differently depending on the number of values that | |
| 328 the user of the function has requested. The implicit assignment to the | |
| 329 built-in variable @code{ans} does not figure in the count of output | |
| 330 arguments, so the value of @code{nargout} may be zero. | |
| 331 | |
| 332 The @code{svd} and @code{lu} functions are examples of built-in | |
| 333 functions that behave differently depending on the value of | |
| 334 @code{nargout}. | |
| 335 | |
| 336 It is possible to write functions that only set some return values. For | |
| 337 example, calling the function | |
| 338 | |
| 339 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
340 @group |
| 3294 | 341 function [x, y, z] = f () |
| 342 x = 1; | |
| 343 z = 2; | |
| 344 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
345 @end group |
| 3294 | 346 @end example |
| 347 | |
| 348 @noindent | |
| 349 as | |
| 350 | |
| 351 @example | |
| 352 [a, b, c] = f () | |
| 353 @end example | |
| 354 | |
| 355 @noindent | |
| 356 produces: | |
| 357 | |
| 358 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
359 @group |
| 3294 | 360 a = 1 |
| 361 | |
| 362 b = [](0x0) | |
| 363 | |
| 364 c = 2 | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
365 @end group |
| 3294 | 366 @end example |
| 367 | |
| 368 @noindent | |
| 6501 | 369 along with a warning. |
| 3294 | 370 |
| 4700 | 371 @DOCSTRING(nargout) |
| 3294 | 372 |
|
12629
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
373 It is good practice at the head of a function to verify that it has been called |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
374 correctly. In Octave the following idiom is seen frequently |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
375 |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
376 @example |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
377 @group |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
378 if (nargin < min_#_inputs || nargin > max_#_inputs) |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
379 print_usage (); |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
380 endif |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
381 @end group |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
382 @end example |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
383 |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
384 @noindent |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
385 which stops the function execution and prints a message about the correct |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
386 way to call the function whenever the number of inputs is wrong. |
|
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
387 |
|
13852
e36817e2ee60
New function narginchk
Carnë Draug <carandraug+dev@gmail.com>
parents:
13749
diff
changeset
|
388 For compatibility with @sc{matlab}, @code{nargchk}, @code{narginchk} and |
|
e36817e2ee60
New function narginchk
Carnë Draug <carandraug+dev@gmail.com>
parents:
13749
diff
changeset
|
389 @code{nargoutchk} are available which provide similar error checking. |
|
12629
8c25df502846
func.txi: document use of nargin checking at head of function.
Rik <octave@nomad.inbox5.com>
parents:
12592
diff
changeset
|
390 |
| 3371 | 391 @DOCSTRING(nargchk) |
| 3294 | 392 |
|
13852
e36817e2ee60
New function narginchk
Carnë Draug <carandraug+dev@gmail.com>
parents:
13749
diff
changeset
|
393 @DOCSTRING(narginchk) |
|
e36817e2ee60
New function narginchk
Carnë Draug <carandraug+dev@gmail.com>
parents:
13749
diff
changeset
|
394 |
|
7984
bbaa5d7d0143
Some documentation updates
David Bateman <dbateman@free.fr>
parents:
7638
diff
changeset
|
395 @DOCSTRING(nargoutchk) |
|
bbaa5d7d0143
Some documentation updates
David Bateman <dbateman@free.fr>
parents:
7638
diff
changeset
|
396 |
|
8286
6f2d95255911
fix @seealso references to point to existing anchors
Thorsten Meyer <thorsten.meyier@gmx.de>
parents:
8276
diff
changeset
|
397 @anchor{doc-varargin} @anchor{doc-varargout} |
| 4167 | 398 @node Variable-length Argument Lists |
| 3294 | 399 @section Variable-length Argument Lists |
| 4933 | 400 @cindex variable-length argument lists |
| 8567 | 401 @cindex @code{varargin} |
| 8072 | 402 |
| 6510 | 403 Sometimes the number of input arguments is not known when the function |
| 404 is defined. As an example think of a function that returns the smallest | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
405 of all its input arguments. For example: |
| 6510 | 406 |
| 407 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
408 @group |
| 6510 | 409 a = smallest (1, 2, 3); |
| 410 b = smallest (1, 2, 3, 4); | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
411 @end group |
| 6510 | 412 @end example |
| 413 | |
| 414 @noindent | |
| 415 In this example both @code{a} and @code{b} would be 1. One way to write | |
| 416 the @code{smallest} function is | |
| 417 | |
| 418 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
419 @group |
| 6510 | 420 function val = smallest (arg1, arg2, arg3, arg4, arg5) |
| 421 @var{body} | |
| 422 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
423 @end group |
| 6510 | 424 @end example |
| 425 | |
| 426 @noindent | |
| 427 and then use the value of @code{nargin} to determine which of the input | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
428 arguments should be considered. The problem with this approach is |
| 6510 | 429 that it can only handle a limited number of input arguments. |
| 430 | |
|
7588
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
431 If the special parameter name @code{varargin} appears at the end of a |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
432 function parameter list it indicates that the function takes a variable |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
433 number of input arguments. Using @code{varargin} the function |
| 6510 | 434 looks like this |
| 435 | |
| 436 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
437 @group |
| 6510 | 438 function val = smallest (varargin) |
| 439 @var{body} | |
| 440 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
441 @end group |
| 6510 | 442 @end example |
| 443 | |
| 444 @noindent | |
| 445 In the function body the input arguments can be accessed through the | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
446 variable @code{varargin}. This variable is a cell array containing |
|
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
447 all the input arguments. @xref{Cell Arrays}, for details on working |
|
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
448 with cell arrays. The @code{smallest} function can now be defined |
| 6510 | 449 like this |
| 450 | |
| 451 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
452 @group |
| 6510 | 453 function val = smallest (varargin) |
| 454 val = min ([varargin@{:@}]); | |
| 455 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
456 @end group |
| 6510 | 457 @end example |
| 458 | |
| 459 @noindent | |
| 460 This implementation handles any number of input arguments, but it's also | |
| 461 a very simple solution to the problem. | |
| 462 | |
| 463 A slightly more complex example of @code{varargin} is a function | |
| 464 @code{print_arguments} that prints all input arguments. Such a function | |
| 465 can be defined like this | |
| 466 | |
| 467 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
468 @group |
| 6510 | 469 function print_arguments (varargin) |
| 470 for i = 1:length (varargin) | |
| 471 printf ("Input argument %d: ", i); | |
| 472 disp (varargin@{i@}); | |
| 473 endfor | |
| 474 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
475 @end group |
| 6510 | 476 @end example |
| 477 | |
| 478 @noindent | |
| 479 This function produces output like this | |
| 480 | |
| 481 @example | |
| 482 @group | |
| 483 print_arguments (1, "two", 3); | |
| 484 @print{} Input argument 1: 1 | |
| 485 @print{} Input argument 2: two | |
| 486 @print{} Input argument 3: 3 | |
| 487 @end group | |
| 488 @end example | |
| 3294 | 489 |
| 6558 | 490 @DOCSTRING(parseparams) |
| 491 | |
|
10209
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
492 @node Ignoring Arguments |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
493 @section Ignoring Arguments |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
494 |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
495 In the formal argument list, it is possible to use the dummy placeholder |
|
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
496 @code{~} instead of a name. This indicates that the corresponding argument |
|
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
497 value should be ignored and not stored to any variable. |
|
10209
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
498 |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
499 @example |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
500 @group |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
501 function val = pick2nd (~, arg2) |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
502 val = arg2; |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
503 endfunction |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
504 @end group |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
505 @end example |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
506 |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
507 The value of @code{nargin} is not affected by using this declaration. |
|
ea0d83b4470b
document use of ~ placeholders in the manual
Jaroslav Hajek <highegg@gmail.com>
parents:
9209
diff
changeset
|
508 |
|
12592
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
509 Return arguments can also be ignored using the same syntax. Functions may |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
510 take advantage of ignored outputs to reduce the number of calculations |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
511 performed. To do so, use the @code{isargout} function to query whether the |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
512 output argument is wanted. For example: |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
513 |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
514 @example |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
515 @group |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
516 function [out1, out2] = long_function (x, y, z) |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
517 if (isargout (1)) |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
518 ## Long calculation |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
519 @dots{} |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
520 out1 = result; |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
521 endif |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
522 @dots{} |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
523 endfunction |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
524 @end group |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
525 @end example |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
526 |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
527 @DOCSTRING(isargout) |
|
732a568bf694
Modify func.txi discussion of output arguments to include discussion of isargout.
Rik <octave@nomad.inbox5.com>
parents:
11573
diff
changeset
|
528 |
| 4167 | 529 @node Variable-length Return Lists |
| 3294 | 530 @section Variable-length Return Lists |
| 4933 | 531 @cindex variable-length return lists |
| 8567 | 532 @cindex @code{varargout} |
| 8072 | 533 |
| 6510 | 534 It is possible to return a variable number of output arguments from a |
| 535 function using a syntax that's similar to the one used with the | |
|
7588
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
536 special @code{varargin} parameter name. To let a function return a |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
537 variable number of output arguments the special output parameter name |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
538 @code{varargout} is used. As with @code{varargin}, @code{varargout} is |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
539 a cell array that will contain the requested output arguments. |
| 6510 | 540 |
| 541 As an example the following function sets the first output argument to | |
| 542 1, the second to 2, and so on. | |
| 543 | |
| 544 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
545 @group |
| 6510 | 546 function varargout = one_to_n () |
| 547 for i = 1:nargout | |
| 548 varargout@{i@} = i; | |
| 549 endfor | |
| 550 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
551 @end group |
| 6510 | 552 @end example |
| 553 | |
| 554 @noindent | |
| 555 When called this function returns values like this | |
| 556 | |
| 557 @example | |
| 558 @group | |
| 559 [a, b, c] = one_to_n () | |
| 560 @result{} a = 1 | |
| 561 @result{} b = 2 | |
| 562 @result{} c = 3 | |
| 563 @end group | |
| 564 @end example | |
| 3294 | 565 |
|
7588
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
566 If @code{varargin} (@code{varargout}) does not appear as the last |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
567 element of the input (output) parameter list, then it is not special, |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
568 and is handled the same as any other parameter name. |
|
cbedf652a752
doc fix for varargin and varargout change
John W. Eaton <jwe@octave.org>
parents:
7031
diff
changeset
|
569 |
| 6558 | 570 @DOCSTRING(deal) |
| 571 | |
|
11255
d682cd6669ac
Update info-based documentation menus to include new nodes.
Rik <octave@nomad.inbox5.com>
parents:
10828
diff
changeset
|
572 @node Returning from a Function |
|
d682cd6669ac
Update info-based documentation menus to include new nodes.
Rik <octave@nomad.inbox5.com>
parents:
10828
diff
changeset
|
573 @section Returning from a Function |
| 3294 | 574 |
| 575 The body of a user-defined function can contain a @code{return} statement. | |
| 576 This statement returns control to the rest of the Octave program. It | |
| 577 looks like this: | |
| 578 | |
| 579 @example | |
| 580 return | |
| 581 @end example | |
| 582 | |
| 583 Unlike the @code{return} statement in C, Octave's @code{return} | |
| 584 statement cannot be used to return a value from a function. Instead, | |
| 585 you must assign values to the list of return variables that are part of | |
| 586 the @code{function} statement. The @code{return} statement simply makes | |
| 587 it easier to exit a function from a deeply nested loop or conditional | |
| 588 statement. | |
| 589 | |
| 590 Here is an example of a function that checks to see if any elements of a | |
| 591 vector are nonzero. | |
| 592 | |
| 593 @example | |
| 594 @group | |
| 595 function retval = any_nonzero (v) | |
| 596 retval = 0; | |
| 597 for i = 1:length (v) | |
| 598 if (v (i) != 0) | |
| 599 retval = 1; | |
| 600 return; | |
| 601 endif | |
| 602 endfor | |
| 603 printf ("no nonzero elements found\n"); | |
| 604 endfunction | |
| 605 @end group | |
| 606 @end example | |
| 607 | |
| 608 Note that this function could not have been written using the | |
| 609 @code{break} statement to exit the loop once a nonzero value is found | |
| 610 without adding extra logic to avoid printing the message if the vector | |
| 611 does contain a nonzero element. | |
| 612 | |
| 11547 | 613 @deftypefn {Keyword} {} return |
| 3294 | 614 When Octave encounters the keyword @code{return} inside a function or |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
615 script, it returns control to the caller immediately. At the top level, |
| 3294 | 616 the return statement is ignored. A @code{return} statement is assumed |
| 617 at the end of every function definition. | |
| 11547 | 618 @end deftypefn |
| 3294 | 619 |
| 6510 | 620 @node Default Arguments |
| 621 @section Default Arguments | |
| 622 @cindex default arguments | |
| 623 | |
| 624 Since Octave supports variable number of input arguments, it is very useful | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
625 to assign default values to some input arguments. When an input argument |
| 6510 | 626 is declared in the argument list it is possible to assign a default |
| 627 value to the argument like this | |
| 628 | |
| 629 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
630 @group |
| 6510 | 631 function @var{name} (@var{arg1} = @var{val1}, @dots{}) |
| 632 @var{body} | |
| 633 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
634 @end group |
| 6510 | 635 @end example |
| 636 | |
| 637 @noindent | |
| 638 If no value is assigned to @var{arg1} by the user, it will have the | |
| 639 value @var{val1}. | |
| 640 | |
| 641 As an example, the following function implements a variant of the classic | |
| 642 ``Hello, World'' program. | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
643 |
| 6510 | 644 @example |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
645 @group |
| 6510 | 646 function hello (who = "World") |
| 647 printf ("Hello, %s!\n", who); | |
| 648 endfunction | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
649 @end group |
| 6510 | 650 @end example |
| 651 | |
| 652 @noindent | |
| 653 When called without an input argument the function prints the following | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
654 |
| 6510 | 655 @example |
| 656 @group | |
| 657 hello (); | |
| 658 @print{} Hello, World! | |
| 659 @end group | |
| 660 @end example | |
| 661 | |
| 662 @noindent | |
| 663 and when it's called with an input argument it prints the following | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
664 |
| 6510 | 665 @example |
| 666 @group | |
| 667 hello ("Beautiful World of Free Software"); | |
| 668 @print{} Hello, Beautiful World of Free Software! | |
| 669 @end group | |
| 670 @end example | |
| 671 | |
| 672 Sometimes it is useful to explicitly tell Octave to use the default value | |
| 673 of an input argument. This can be done writing a @samp{:} as the value | |
| 674 of the input argument when calling the function. | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
675 |
| 6510 | 676 @example |
| 677 @group | |
| 678 hello (:); | |
| 679 @print{} Hello, World! | |
| 680 @end group | |
| 681 @end example | |
| 682 | |
| 4167 | 683 @node Function Files |
| 3294 | 684 @section Function Files |
| 685 @cindex function file | |
| 686 | |
| 687 Except for simple one-shot programs, it is not practical to have to | |
| 688 define all the functions you need each time you need them. Instead, you | |
| 689 will normally want to save them in a file so that you can easily edit | |
| 690 them, and save them for use at a later time. | |
| 691 | |
| 692 Octave does not require you to load function definitions from files | |
| 693 before using them. You simply need to put the function definitions in a | |
| 694 place where Octave can find them. | |
| 695 | |
| 696 When Octave encounters an identifier that is undefined, it first looks | |
| 697 for variables or functions that are already compiled and currently | |
| 698 listed in its symbol table. If it fails to find a definition there, it | |
| 6556 | 699 searches a list of directories (the @dfn{path}) for files ending in |
| 6554 | 700 @file{.m} that have the same base name as the undefined |
| 701 identifier.@footnote{The @samp{.m} suffix was chosen for compatibility | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
702 with @sc{matlab}.} Once Octave finds a file with a name that matches, |
| 6554 | 703 the contents of the file are read. If it defines a @emph{single} |
| 704 function, it is compiled and executed. @xref{Script Files}, for more | |
| 705 information about how you can define more than one function in a single | |
| 706 file. | |
| 3294 | 707 |
| 708 When Octave defines a function from a function file, it saves the full | |
| 6554 | 709 name of the file it read and the time stamp on the file. If the time |
| 710 stamp on the file changes, Octave may reload the file. When Octave is | |
| 711 running interactively, time stamp checking normally happens at most once | |
| 712 each time Octave prints the prompt. Searching for new function | |
| 713 definitions also occurs if the current working directory changes. | |
| 3294 | 714 |
| 715 Checking the time stamp allows you to edit the definition of a function | |
| 716 while Octave is running, and automatically use the new function | |
| 6554 | 717 definition without having to restart your Octave session. |
| 3294 | 718 |
| 719 To avoid degrading performance unnecessarily by checking the time stamps | |
| 720 on functions that are not likely to change, Octave assumes that function | |
| 721 files in the directory tree | |
| 722 @file{@var{octave-home}/share/octave/@var{version}/m} | |
| 723 will not change, so it doesn't have to check their time stamps every time the | |
| 724 functions defined in those files are used. This is normally a very good | |
| 725 assumption and provides a significant improvement in performance for the | |
| 726 function files that are distributed with Octave. | |
| 727 | |
| 728 If you know that your own function files will not change while you are | |
| 6554 | 729 running Octave, you can improve performance by calling |
| 730 @code{ignore_function_time_stamp ("all")}, so that Octave will | |
| 731 ignore the time stamps for all function files. Passing | |
| 732 @code{"system"} to this function resets the default behavior. | |
| 3294 | 733 |
| 5775 | 734 @c FIXME -- note about time stamps on files in NFS environments? |
| 3294 | 735 |
|
8817
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
736 @DOCSTRING(edit) |
|
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
737 |
| 6549 | 738 @DOCSTRING(mfilename) |
| 739 | |
| 6638 | 740 @DOCSTRING(ignore_function_time_stamp) |
| 741 | |
| 742 @menu | |
|
11255
d682cd6669ac
Update info-based documentation menus to include new nodes.
Rik <octave@nomad.inbox5.com>
parents:
10828
diff
changeset
|
743 * Manipulating the Load Path:: |
| 6638 | 744 * Subfunctions:: |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
745 * Private Functions:: |
| 6638 | 746 * Overloading and Autoloading:: |
| 747 * Function Locking:: | |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
748 * Function Precedence:: |
| 6638 | 749 @end menu |
| 750 | |
|
11257
8d4c57258523
fix some menu problems in the manual
John W. Eaton <jwe@octave.org>
parents:
11255
diff
changeset
|
751 @node Manipulating the Load Path |
|
8d4c57258523
fix some menu problems in the manual
John W. Eaton <jwe@octave.org>
parents:
11255
diff
changeset
|
752 @subsection Manipulating the Load Path |
| 6638 | 753 |
| 8828 | 754 When a function is called, Octave searches a list of directories for |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
755 a file that contains the function declaration. This list of directories |
|
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
756 is known as the load path. By default the load path contains |
| 6638 | 757 a list of directories distributed with Octave plus the current |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
758 working directory. To see your current load path call the @code{path} |
| 6638 | 759 function without any input or output arguments. |
| 760 | |
| 761 It is possible to add or remove directories to or from the load path | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
762 using @code{addpath} and @code{rmpath}. As an example, the following |
| 6638 | 763 code adds @samp{~/Octave} to the load path. |
| 764 | |
| 765 @example | |
| 766 addpath("~/Octave") | |
| 767 @end example | |
| 768 | |
| 769 @noindent | |
| 770 After this the directory @samp{~/Octave} will be searched for functions. | |
| 771 | |
| 6502 | 772 @DOCSTRING(addpath) |
| 773 | |
| 774 @DOCSTRING(genpath) | |
| 775 | |
| 776 @DOCSTRING(rmpath) | |
| 777 | |
| 778 @DOCSTRING(savepath) | |
| 779 | |
| 6477 | 780 @DOCSTRING(path) |
| 3294 | 781 |
| 6502 | 782 @DOCSTRING(pathdef) |
| 783 | |
| 784 @DOCSTRING(pathsep) | |
| 785 | |
| 3428 | 786 @DOCSTRING(rehash) |
| 787 | |
| 788 @DOCSTRING(file_in_loadpath) | |
| 789 | |
|
7638
2df457529cfa
implement expm1 and log1p functions
Jaroslav Hajek <highegg@gmail.com>
parents:
7588
diff
changeset
|
790 @DOCSTRING(restoredefaultpath) |
|
2df457529cfa
implement expm1 and log1p functions
Jaroslav Hajek <highegg@gmail.com>
parents:
7588
diff
changeset
|
791 |
|
8817
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
792 @DOCSTRING(command_line_path) |
|
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
793 |
|
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
794 @DOCSTRING(find_dir_in_path) |
|
03b7f618ab3d
include docstrings for new functions in the manual
John W. Eaton <jwe@octave.org>
parents:
8567
diff
changeset
|
795 |
| 6556 | 796 @node Subfunctions |
| 797 @subsection Subfunctions | |
| 798 | |
| 799 A function file may contain secondary functions called | |
| 800 @dfn{subfunctions}. These secondary functions are only visible to the | |
| 801 other functions in the same function file. For example, a file | |
| 802 @file{f.m} containing | |
| 803 | |
| 804 @example | |
| 805 @group | |
| 806 function f () | |
| 807 printf ("in f, calling g\n"); | |
| 808 g () | |
| 809 endfunction | |
| 810 function g () | |
| 811 printf ("in g, calling h\n"); | |
| 6638 | 812 h () |
| 6556 | 813 endfunction |
| 814 function h () | |
| 815 printf ("in h\n") | |
| 816 endfunction | |
| 817 @end group | |
| 818 @end example | |
| 819 | |
| 820 @noindent | |
| 821 defines a main function @code{f} and two subfunctions. The | |
| 822 subfunctions @code{g} and @code{h} may only be called from the main | |
| 823 function @code{f} or from the other subfunctions, but not from outside | |
| 824 the file @file{f.m}. | |
| 825 | |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
826 @node Private Functions |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
827 @subsection Private Functions |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
828 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
829 In many cases one function needs to access one or more helper |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
830 functions. If the helper function is limited to the scope of a single |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
831 function, then subfunctions as discussed above might be used. However, |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
832 if a single helper function is used by more than one function, then |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
833 this is no longer possible. In this case the helper functions might |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
834 be placed in a subdirectory, called "private", of the directory in which |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
835 the functions needing access to this helper function are found. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
836 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
837 As a simple example, consider a function @code{func1}, that calls a helper |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
838 function @code{func2} to do much of the work. For example: |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
839 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
840 @example |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
841 @group |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
842 function y = func1 (x) |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
843 y = func2 (x); |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
844 endfunction |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
845 @end group |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
846 @end example |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
847 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
848 @noindent |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
849 Then if the path to @code{func1} is @code{<directory>/func1.m}, and if |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
850 @code{func2} is found in the directory @code{<directory>/private/func2.m}, |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
851 then @code{func2} is only available for use of the functions, like |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
852 @code{func1}, that are found in @code{<directory>}. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
853 |
| 6635 | 854 @node Overloading and Autoloading |
| 855 @subsection Overloading and Autoloading | |
| 856 | |
|
11396
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
857 Functions can be overloaded to work with different input arguments. For |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
858 example, the operator '+' has been overloaded in Octave to work with single, |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
859 double, uint8, int32, and many other arguments. The preferred way to overload |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
860 functions is through classes and object oriented programming |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
861 (@pxref{Function Overloading}). Occasionally, however, one needs to undo |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
862 user overloading and call the default function associated with a specific |
|
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
863 type. The @code{builtin} function exists for this purpose. |
| 6635 | 864 |
| 865 @DOCSTRING(builtin) | |
| 866 | |
| 867 A single dynamically linked file might define several | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
868 functions. However, as Octave searches for functions based on the |
| 6635 | 869 functions filename, Octave needs a manner in which to find each of the |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
870 functions in the dynamically linked file. On operating systems that |
| 6635 | 871 support symbolic links, it is possible to create a symbolic link to the |
| 872 original file for each of the functions which it contains. | |
| 873 | |
| 874 However, there is at least one well known operating system that doesn't | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
875 support symbolic links. Making copies of the original file for each of |
| 8828 | 876 the functions is undesirable as it increases the |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
877 amount of disk space used by Octave. Instead Octave supplies the |
| 6635 | 878 @code{autoload} function, that permits the user to define in which |
| 879 file a certain function will be found. | |
| 880 | |
| 881 @DOCSTRING(autoload) | |
| 882 | |
| 883 @node Function Locking | |
| 884 @subsection Function Locking | |
| 885 | |
| 886 It is sometime desirable to lock a function into memory with the | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
887 @code{mlock} function. This is typically used for dynamically linked |
| 6899 | 888 functions in Oct-files or mex-files that contain some initialization, |
| 889 and it is desirable that calling @code{clear} does not remove this | |
| 6635 | 890 initialization. |
| 891 | |
| 6899 | 892 As an example, |
| 893 | |
| 894 @example | |
| 895 mlock ("my_function"); | |
| 896 @end example | |
| 897 | |
| 898 @noindent | |
| 899 prevents @code{my_function} from being removed from memory, even if | |
| 900 @code{clear} is called. It is possible to determine if a function is | |
| 901 locked into memory with the @code{mislocked}, and to unlock a function | |
| 902 with @code{munlock}, which the following illustrates. | |
| 903 | |
| 904 @example | |
| 905 @group | |
| 906 mlock ("my_function"); | |
| 907 mislocked ("my_function") | |
| 908 @result{} ans = 1 | |
| 909 munlock ("my_function"); | |
| 910 mislocked ("my_function") | |
| 911 @result{} ans = 0 | |
| 912 @end group | |
| 913 @end example | |
| 914 | |
| 915 A common use of @code{mlock} is to prevent persistent variables from | |
| 8828 | 916 being removed from memory, as the following example shows: |
| 6899 | 917 |
| 918 @example | |
| 919 @group | |
| 920 function count_calls() | |
| 921 persistent calls = 0; | |
| 7031 | 922 printf ("'count_calls' has been called %d times\n", |
| 923 ++calls); | |
| 6899 | 924 endfunction |
| 925 mlock ("count_calls"); | |
| 926 | |
| 927 count_calls (); | |
| 928 @print{} 'count_calls' has been called 1 times | |
| 929 | |
| 930 clear count_calls | |
| 931 count_calls (); | |
| 932 @print{} 'count_calls' has been called 2 times | |
| 933 @end group | |
| 934 @end example | |
| 935 | |
| 936 @noindent | |
| 937 It is, however, often inconvenient to lock a function from the prompt, | |
| 938 so it is also possible to lock a function from within its body. This | |
| 939 is simply done by calling @code{mlock} from within the function. | |
| 940 | |
| 941 @example | |
| 942 @group | |
| 943 function count_calls () | |
| 944 mlock (); | |
| 945 persistent calls = 0; | |
| 7031 | 946 printf ("'count_calls' has been called %d times\n", |
| 947 ++calls); | |
| 6899 | 948 endfunction |
| 949 @end group | |
| 950 @end example | |
| 951 | |
| 952 @code{mlock} might equally be used to prevent changes to a function from having | |
| 6635 | 953 effect in Octave, though a similar effect can be had with the |
| 954 @code{ignore_function_time_stamp} function. | |
| 955 | |
| 956 @DOCSTRING(mlock) | |
| 957 | |
| 958 @DOCSTRING(munlock) | |
| 959 | |
| 960 @DOCSTRING(mislocked) | |
| 961 | |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
962 @node Function Precedence |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
963 @subsection Function Precedence |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
964 |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
965 Given the numerous different ways that Octave can define a function, it |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
966 is possible and even likely that multiple versions of a function, might be |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
967 defined within a particular scope. The precedence of which function will be |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
968 used within a particular scope is given by |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
969 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
970 @enumerate 1 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
971 @item Subfunction |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
972 A subfunction with the required function name in the given scope. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
973 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
974 @item Private function |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
975 A function defined within a private directory of the directory |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
976 which contains the current function. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
977 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
978 @item Class constructor |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
979 A function that constuctors a user class as defined in chapter |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
980 @ref{Object Oriented Programming}. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
981 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
982 @item Class method |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
983 An overloaded function of a class as in chapter |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
984 @ref{Object Oriented Programming}. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
985 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
986 @item Legacy Dispatch |
|
11396
7b563cf94d8d
Remove documentation on deprecated function dispatch
Rik <octave@nomad.inbox5.com>
parents:
11392
diff
changeset
|
987 An overloaded function as defined by @code{dispatch}. |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
988 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
989 @item Command-line Function |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
990 A function that has been defined on the command-line. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
991 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
992 @item Autoload function |
| 8235 | 993 A function that is marked as autoloaded with @xref{doc-autoload}. |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
994 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
995 @item A Function on the Path |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
996 A function that can be found on the users load-path. There can also be |
|
8221
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
997 Oct-file, mex-file or m-file versions of this function and the precedence |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
998 between these versions are in that order. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
999 |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
1000 @item Built-in function |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
1001 A function that is builtin to Octave itself such as @code{numel}, |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
1002 @code{size}, etc. |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
1003 @end enumerate |
|
06094fa570a3
Add some documentation for the OOP code of Octave
David Bateman <dbateman@free.fr>
parents:
8074
diff
changeset
|
1004 |
| 4167 | 1005 @node Script Files |
| 3294 | 1006 @section Script Files |
| 1007 | |
| 1008 A script file is a file containing (almost) any sequence of Octave | |
| 1009 commands. It is read and evaluated just as if you had typed each | |
| 1010 command at the Octave prompt, and provides a convenient way to perform a | |
| 1011 sequence of commands that do not logically belong inside a function. | |
| 1012 | |
| 1013 Unlike a function file, a script file must @emph{not} begin with the | |
| 1014 keyword @code{function}. If it does, Octave will assume that it is a | |
| 1015 function file, and that it defines a single function that should be | |
| 1016 evaluated as soon as it is defined. | |
| 1017 | |
| 1018 A script file also differs from a function file in that the variables | |
| 1019 named in a script file are not local variables, but are in the same | |
| 1020 scope as the other variables that are visible on the command line. | |
| 1021 | |
| 1022 Even though a script file may not begin with the @code{function} | |
| 1023 keyword, it is possible to define more than one function in a single | |
| 1024 script file and load (but not execute) all of them at once. To do | |
| 1025 this, the first token in the file (ignoring comments and other white | |
| 1026 space) must be something other than @code{function}. If you have no | |
| 1027 other statements to evaluate, you can use a statement that has no | |
| 1028 effect, like this: | |
| 1029 | |
| 1030 @example | |
| 1031 @group | |
| 1032 # Prevent Octave from thinking that this | |
| 1033 # is a function file: | |
| 1034 | |
| 1035 1; | |
| 1036 | |
| 1037 # Define function one: | |
| 1038 | |
| 1039 function one () | |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1040 @dots{} |
| 3294 | 1041 @end group |
| 1042 @end example | |
| 1043 | |
| 1044 To have Octave read and compile these functions into an internal form, | |
| 6638 | 1045 you need to make sure that the file is in Octave's load path |
| 6477 | 1046 (accessible through the @code{path} function), then simply type the |
| 1047 base name of the file that contains the commands. (Octave uses the | |
| 1048 same rules to search for script files as it does to search for | |
| 1049 function files.) | |
| 3294 | 1050 |
| 1051 If the first token in a file (ignoring comments) is @code{function}, | |
| 1052 Octave will compile the function and try to execute it, printing a | |
| 1053 message warning about any non-whitespace characters that appear after | |
| 1054 the function definition. | |
| 1055 | |
| 1056 Note that Octave does not try to look up the definition of any identifier | |
| 1057 until it needs to evaluate it. This means that Octave will compile the | |
| 1058 following statements if they appear in a script file, or are typed at | |
| 1059 the command line, | |
| 1060 | |
| 1061 @example | |
| 1062 @group | |
| 1063 # not a function file: | |
| 1064 1; | |
| 1065 function foo () | |
| 1066 do_something (); | |
| 1067 endfunction | |
| 1068 function do_something () | |
| 1069 do_something_else (); | |
| 1070 endfunction | |
| 1071 @end group | |
| 1072 @end example | |
| 1073 | |
| 1074 @noindent | |
| 1075 even though the function @code{do_something} is not defined before it is | |
| 1076 referenced in the function @code{foo}. This is not an error because | |
| 1077 Octave does not need to resolve all symbols that are referenced by a | |
| 1078 function until the function is actually evaluated. | |
| 1079 | |
| 1080 Since Octave doesn't look for definitions until they are needed, the | |
| 1081 following code will always print @samp{bar = 3} whether it is typed | |
| 1082 directly on the command line, read from a script file, or is part of a | |
| 1083 function body, even if there is a function or script file called | |
| 6477 | 1084 @file{bar.m} in Octave's path. |
| 3294 | 1085 |
| 1086 @example | |
| 1087 @group | |
| 1088 eval ("bar = 3"); | |
| 1089 bar | |
| 1090 @end group | |
| 1091 @end example | |
| 1092 | |
| 1093 Code like this appearing within a function body could fool Octave if | |
| 1094 definitions were resolved as the function was being compiled. It would | |
| 1095 be virtually impossible to make Octave clever enough to evaluate this | |
| 1096 code in a consistent fashion. The parser would have to be able to | |
| 1097 perform the call to @code{eval} at compile time, and that would be | |
| 1098 impossible unless all the references in the string to be evaluated could | |
| 1099 also be resolved, and requiring that would be too restrictive (the | |
| 1100 string might come from user input, or depend on things that are not | |
| 1101 known until the function is evaluated). | |
| 1102 | |
| 1103 Although Octave normally executes commands from script files that have | |
| 1104 the name @file{@var{file}.m}, you can use the function @code{source} to | |
| 1105 execute commands from any file. | |
| 1106 | |
| 3371 | 1107 @DOCSTRING(source) |
| 3294 | 1108 |
| 6638 | 1109 @node Function Handles Inline Functions and Anonymous Functions |
| 1110 @section Function Handles, Inline Functions, and Anonymous Functions | |
| 4933 | 1111 @cindex handle, function handles |
| 1112 @cindex inline, inline functions | |
| 6638 | 1113 @cindex anonymous functions |
| 4933 | 1114 |
| 6638 | 1115 It can be very convenient store a function in a variable so that it |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1116 can be passed to a different function. For example, a function that |
|
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1117 performs numerical minimization needs access to the function that |
|
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1118 should be minimized. |
| 4933 | 1119 |
| 1120 @menu | |
| 1121 * Function Handles:: | |
| 6554 | 1122 * Anonymous Functions:: |
| 4933 | 1123 * Inline Functions:: |
| 1124 @end menu | |
| 1125 | |
| 1126 @node Function Handles | |
| 1127 @subsection Function Handles | |
| 1128 | |
| 6554 | 1129 A function handle is a pointer to another function and is defined with |
| 1130 the syntax | |
| 1131 | |
| 1132 @example | |
| 1133 @@@var{function-name} | |
| 1134 @end example | |
| 1135 | |
| 1136 @noindent | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
1137 For example, |
| 6554 | 1138 |
| 1139 @example | |
| 6556 | 1140 f = @@sin; |
| 6554 | 1141 @end example |
| 1142 | |
| 1143 @noindent | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
1144 creates a function handle called @code{f} that refers to the |
| 6554 | 1145 function @code{sin}. |
| 1146 | |
| 1147 Function handles are used to call other functions indirectly, or to pass | |
| 1148 a function as an argument to another function like @code{quad} or | |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
1149 @code{fsolve}. For example: |
| 6554 | 1150 |
| 1151 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1152 @group |
| 6556 | 1153 f = @@sin; |
| 6554 | 1154 quad (f, 0, pi) |
| 6929 | 1155 @result{} 2 |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1156 @end group |
| 6554 | 1157 @end example |
| 1158 | |
| 1159 You may use @code{feval} to call a function using function handle, or | |
| 6570 | 1160 simply write the name of the function handle followed by an argument |
| 6554 | 1161 list. If there are no arguments, you must use an empty argument list |
|
10828
322f43e0e170
Grammarcheck .txi documentation files.
Rik <octave@nomad.inbox5.com>
parents:
10711
diff
changeset
|
1162 @samp{()}. For example: |
| 6554 | 1163 |
| 1164 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1165 @group |
| 6556 | 1166 f = @@sin; |
| 6554 | 1167 feval (f, pi/4) |
| 6570 | 1168 @result{} 0.70711 |
| 6554 | 1169 f (pi/4) |
| 6570 | 1170 @result{} 0.70711 |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1171 @end group |
| 6554 | 1172 @end example |
| 1173 | |
|
14175
3972c4caa60a
Add new function is_function_handle (patch #7695)
Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
parents:
14138
diff
changeset
|
1174 @DOCSTRING(is_function_handle) |
|
3972c4caa60a
Add new function is_function_handle (patch #7695)
Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
parents:
14138
diff
changeset
|
1175 |
| 4933 | 1176 @DOCSTRING(functions) |
| 1177 | |
| 1178 @DOCSTRING(func2str) | |
| 1179 | |
| 1180 @DOCSTRING(str2func) | |
| 1181 | |
| 6570 | 1182 @node Anonymous Functions |
| 6554 | 1183 @subsection Anonymous Functions |
| 1184 | |
| 1185 Anonymous functions are defined using the syntax | |
| 1186 | |
| 1187 @example | |
| 1188 @@(@var{argument-list}) @var{expression} | |
| 1189 @end example | |
| 1190 | |
| 1191 @noindent | |
| 1192 Any variables that are not found in the argument list are inherited from | |
| 1193 the enclosing scope. Anonymous functions are useful for creating simple | |
| 1194 unnamed functions from expressions or for wrapping calls to other | |
| 1195 functions to adapt them for use by functions like @code{quad}. For | |
| 1196 example, | |
| 1197 | |
| 1198 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1199 @group |
| 6554 | 1200 f = @@(x) x.^2; |
| 1201 quad (f, 0, 10) | |
| 6570 | 1202 @result{} 333.33 |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1203 @end group |
| 6554 | 1204 @end example |
| 1205 | |
| 1206 @noindent | |
| 1207 creates a simple unnamed function from the expression @code{x.^2} and | |
| 1208 passes it to @code{quad}, | |
| 1209 | |
| 1210 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1211 @group |
| 6554 | 1212 quad (@@(x) sin (x), 0, pi) |
| 6933 | 1213 @result{} 2 |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1214 @end group |
| 6554 | 1215 @end example |
| 1216 | |
| 1217 @noindent | |
| 1218 wraps another function, and | |
| 1219 | |
| 1220 @example | |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1221 @group |
| 6554 | 1222 a = 1; |
| 1223 b = 2; | |
| 1224 quad (@@(x) betainc (x, a, b), 0, 0.4) | |
| 6929 | 1225 @result{} 0.13867 |
|
9209
923c7cb7f13f
Simplify TeXinfo files by eliminating redundant @iftex followed by @tex construction.
Rik <rdrider0-list@yahoo.com>
parents:
9038
diff
changeset
|
1226 @end group |
| 6554 | 1227 @end example |
| 1228 | |
| 1229 @noindent | |
| 1230 adapts a function with several parameters to the form required by | |
| 1231 @code{quad}. In this example, the values of @var{a} and @var{b} that | |
| 1232 are passed to @code{betainc} are inherited from the current | |
| 1233 environment. | |
| 1234 | |
| 4933 | 1235 @node Inline Functions |
| 1236 @subsection Inline Functions | |
| 1237 | |
| 6638 | 1238 An inline function is created from a string containing the function |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1239 body using the @code{inline} function. The following code defines the |
| 6638 | 1240 function @math{f(x) = x^2 + 2}. |
| 1241 | |
| 1242 @example | |
| 1243 f = inline("x^2 + 2"); | |
| 1244 @end example | |
| 1245 | |
| 1246 @noindent | |
| 1247 After this it is possible to evaluate @math{f} at any @math{x} by | |
| 1248 writing @code{f(x)}. | |
| 1249 | |
| 4933 | 1250 @DOCSTRING(inline) |
| 1251 | |
| 1252 @DOCSTRING(argnames) | |
| 1253 | |
| 1254 @DOCSTRING(formula) | |
| 1255 | |
|
7984
bbaa5d7d0143
Some documentation updates
David Bateman <dbateman@free.fr>
parents:
7638
diff
changeset
|
1256 @DOCSTRING(symvar) |
|
bbaa5d7d0143
Some documentation updates
David Bateman <dbateman@free.fr>
parents:
7638
diff
changeset
|
1257 |
| 6549 | 1258 @node Commands |
| 1259 @section Commands | |
| 1260 | |
| 6638 | 1261 Commands are a special class of functions that only accept string |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1262 input arguments. A command can be called as an ordinary function, but |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1263 it can also be called without the parentheses. For example, |
| 6638 | 1264 |
| 1265 @example | |
| 1266 my_command hello world | |
| 1267 @end example | |
| 1268 | |
| 1269 @noindent | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1270 is equivalent to |
| 6638 | 1271 |
| 1272 @example | |
| 1273 my_command("hello", "world") | |
| 1274 @end example | |
| 1275 | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1276 @noindent |
| 6638 | 1277 The general form of a command call is |
| 1278 | |
| 1279 @example | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1280 @var{cmdname} @var{arg1} @var{arg2} @dots{} |
| 6638 | 1281 @end example |
| 1282 | |
| 1283 @noindent | |
| 1284 which translates directly to | |
| 1285 | |
| 1286 @example | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1287 @var{cmdname} ("@var{arg1}", "@var{arg2}", @dots{}) |
| 6638 | 1288 @end example |
| 1289 | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1290 Any regular function can be used as a command if it accepts string input |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1291 arguments. For example: |
|
11573
6f8ffe2c6f76
Grammarcheck txi files for 3.4 release.
Rik <octave@nomad.inbox5.com>
parents:
11547
diff
changeset
|
1292 |
| 6638 | 1293 @example |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1294 @group |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1295 toupper lower_case_arg |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1296 @result{} ans = LOWER_CASE_ARG |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1297 @end group |
| 6638 | 1298 @end example |
| 1299 | |
| 1300 One difficulty of commands occurs when one of the string input arguments | |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1301 is stored in a variable. Because Octave can't tell the difference between |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1302 a variable name and an ordinary string, it is not possible to pass a |
|
9038
fca0dc2fb042
Cleanup documentation files stmt.texi and func.texi
Rik <rdrider0-list@yahoo.com>
parents:
9032
diff
changeset
|
1303 variable as input to a command. In such a situation a command must be |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1304 called as a function. For example: |
| 6549 | 1305 |
|
11392
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1306 @example |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1307 @group |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1308 strvar = "hello world"; |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1309 toupper strvar |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1310 @result{} ans = STRVAR |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1311 toupper (strvar) |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1312 @result{} ans = HELLO WORLD |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1313 @end group |
|
757efa1d7e2a
Remove deprecated functions from manual.
Rik <octave@nomad.inbox5.com>
parents:
11257
diff
changeset
|
1314 @end example |
| 6549 | 1315 |
| 1316 | |
| 4167 | 1317 @node Organization of Functions |
| 3294 | 1318 @section Organization of Functions Distributed with Octave |
| 1319 | |
| 1320 Many of Octave's standard functions are distributed as function files. | |
| 1321 They are loosely organized by topic, in subdirectories of | |
| 1322 @file{@var{octave-home}/lib/octave/@var{version}/m}, to make it easier | |
| 1323 to find them. | |
| 1324 | |
| 1325 The following is a list of all the function file subdirectories, and the | |
| 1326 types of functions you will find there. | |
| 1327 | |
| 1328 @table @file | |
| 1329 @item audio | |
| 1330 Functions for playing and recording sounds. | |
| 1331 | |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1332 @item deprecated |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1333 Out-of-date functions which will eventually be removed from Octave. |
| 3294 | 1334 |
| 1335 @item elfun | |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1336 Elementary functions, principally trigonometric. |
| 3294 | 1337 |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1338 @item @@ftp |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1339 Class functions for the FTP object. |
| 6554 | 1340 |
| 3294 | 1341 @item general |
| 1342 Miscellaneous matrix manipulations, like @code{flipud}, @code{rot90}, | |
| 1343 and @code{triu}, as well as other basic functions, like | |
| 4029 | 1344 @code{ismatrix}, @code{nargchk}, etc. |
| 3294 | 1345 |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1346 @item geometry |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1347 Functions related to Delaunay triangulation. |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1348 |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1349 @item help |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1350 Functions for Octave's built-in help system. |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1351 |
| 3294 | 1352 @item image |
| 1353 Image processing tools. These functions require the X Window System. | |
| 1354 | |
| 1355 @item io | |
|
8325
b93ac0586e4b
spelling corrections
Brian Gough<bjg@network-theory.co.uk>
parents:
8286
diff
changeset
|
1356 Input-output functions. |
| 3294 | 1357 |
| 1358 @item linear-algebra | |
| 1359 Functions for linear algebra. | |
| 1360 | |
| 1361 @item miscellaneous | |
| 1362 Functions that don't really belong anywhere else. | |
| 1363 | |
| 6554 | 1364 @item optimization |
|
12642
f96b9b9f141b
doc: Periodic grammarcheck and spellcheck of documentation.
Rik <octave@nomad.inbox5.com>
parents:
12632
diff
changeset
|
1365 Functions related to minimization, optimization, and root finding. |
| 6554 | 1366 |
| 1367 @item path | |
| 1368 Functions to manage the directory path Octave uses to find functions. | |
| 1369 | |
| 1370 @item pkg | |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1371 Package manager for installing external packages of functions in Octave. |
| 6554 | 1372 |
| 3294 | 1373 @item plot |
| 6556 | 1374 Functions for displaying and printing two- and three-dimensional graphs. |
| 3294 | 1375 |
| 1376 @item polynomial | |
| 1377 Functions for manipulating polynomials. | |
| 1378 | |
|
14133
b25559bd5aaa
doc: Document prefs directory in list of installed script files.
Rik <octave@nomad.inbox5.com>
parents:
14116
diff
changeset
|
1379 @item prefs |
|
b25559bd5aaa
doc: Document prefs directory in list of installed script files.
Rik <octave@nomad.inbox5.com>
parents:
14116
diff
changeset
|
1380 Functions implementing user-defined preferences. |
|
b25559bd5aaa
doc: Document prefs directory in list of installed script files.
Rik <octave@nomad.inbox5.com>
parents:
14116
diff
changeset
|
1381 |
| 3294 | 1382 @item set |
| 1383 Functions for creating and manipulating sets of unique values. | |
| 1384 | |
| 1385 @item signal | |
| 1386 Functions for signal processing applications. | |
| 1387 | |
| 6554 | 1388 @item sparse |
| 1389 Functions for handling sparse matrices. | |
| 1390 | |
| 3294 | 1391 @item specfun |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1392 Special functions such as @code{bessel} or @code{factor}. |
| 3294 | 1393 |
| 1394 @item special-matrix | |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1395 Functions that create special matrix forms such as Hilbert or Vandermonde |
|
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1396 matrices. |
| 3294 | 1397 |
| 1398 @item startup | |
| 1399 Octave's system-wide startup file. | |
| 1400 | |
| 1401 @item statistics | |
| 1402 Statistical functions. | |
| 1403 | |
| 1404 @item strings | |
| 1405 Miscellaneous string-handling functions. | |
| 1406 | |
| 6554 | 1407 @item testfun |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1408 Functions for performing unit tests on other functions. |
| 6554 | 1409 |
| 3294 | 1410 @item time |
|
12632
2dbac27e0e40
doc: miscellaneous touch-ups to documentation strings
Rik <octave@nomad.inbox5.com>
parents:
12629
diff
changeset
|
1411 Functions related to time and date processing. |
| 3294 | 1412 @end table |