Mercurial > hg > octave-nkf
annotate scripts/strings/strchr.m @ 12541:dd2c70b30f28
Add tests for ifftshift.m
| author | Robert T. Short <octave@phaselockedsystems.com.com> |
|---|---|
| date | Sat, 26 Mar 2011 06:50:12 -0700 |
| parents | 26d3164fd58d |
| children | 9da8fbd17b92 |
| rev | line source |
|---|---|
| 11523 | 1 ## Copyright (C) 2008-2011 Jaroslav Hajek |
| 8552 | 2 ## |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
| 7 ## the Free Software Foundation; either version 3 of the License, or (at | |
| 8 ## your option) any later version. | |
| 9 ## | |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 16 ## along with Octave; see the file COPYING. If not, see | |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 18 | |
| 19 ## -*- texinfo -*- | |
|
10793
be55736a0783
Grammarcheck the documentation from m-files.
Rik <octave@nomad.inbox5.com>
parents:
10408
diff
changeset
|
20 ## @deftypefn {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}) |
| 8552 | 21 ## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n}) |
| 8830 | 22 ## @deftypefnx {Function File} {@var{idx} =} strchr (@var{str}, @var{chars}, @var{n}, @var{direction}) |
| 11261 | 23 ## Search for the string @var{str} for occurrences of characters from |
| 24 ## the set @var{chars}. The return value, as well as the @var{n} and | |
| 25 ## @var{direction} arguments behave identically as in @code{find}. | |
| 8552 | 26 ## |
| 27 ## This will be faster than using regexp in most cases. | |
| 28 ## | |
| 29 ## @seealso{find} | |
| 8715 | 30 ## @end deftypefn |
| 8552 | 31 |
| 32 function varargout = strchr (str, chars, varargin) | |
| 33 if (nargin < 2 || ! ischar (str) || ! ischar (chars)) | |
| 34 print_usage (); | |
| 35 endif | |
| 10408 | 36 if (isempty (chars)) |
| 37 mask = false (size (str)); | |
| 38 elseif (length (chars) <= 6) | |
| 39 ## With a few characters, it pays off to build the mask incrementally. | |
| 40 ## We do it via a for loop to save memory. | |
| 41 mask = str == chars(1); | |
| 42 for i = 2:length (chars) | |
| 43 mask |= str == chars(i); | |
| 44 endfor | |
| 45 else | |
| 11261 | 46 ## Index the str into a mask of valid values. This is slower than |
| 47 ## it could be because of the +1 issue. | |
| 10408 | 48 f = false (1, 256); |
|
12474
26d3164fd58d
strchr.m: avoid implict string to number conversion
John W. Eaton <jwe@octave.org>
parents:
11587
diff
changeset
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49 f(uint8(chars)+1) = true; |
| 11261 | 50 ## Default goes via double -- unnecessarily long. |
| 51 si = uint32 (str); | |
| 52 ## in-place | |
| 53 ++si; | |
| 10408 | 54 mask = reshape (f(si), size (str)); |
| 55 endif | |
| 8552 | 56 varargout = cell (1, nargout); |
| 57 varargout{1} = []; | |
| 10408 | 58 [varargout{:}] = find (mask, varargin{:}); |
|
11587
c792872f8942
all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents:
11523
diff
changeset
|
59 endfunction |
| 8552 | 60 |
| 11260 | 61 %!assert(strchr("Octave is the best software",""),zeros(1,0)) |
| 8552 | 62 %!assert(strchr("Octave is the best software","best"),[3, 6, 9, 11, 13, 15, 16, 17, 18, 20, 23, 27]) |
| 11260 | 63 %!assert(strchr("Octave is the best software","software"),[3, 4, 6, 9, 11, 13, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27]) |
| 64 |