|
6239
|
1 ## Copyright (C) 2006 David Bateman <dbateman@free.fr> |
|
|
2 ## |
|
6440
|
3 ## This file is part of Octave. |
|
6239
|
4 ## |
|
6440
|
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 2, or (at your option) |
|
|
8 ## 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. |
|
6239
|
14 ## |
|
|
15 ## You should have received a copy of the GNU General Public License |
|
6440
|
16 ## along with Octave; see the file COPYING. If not, write to the Free |
|
|
17 ## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
|
|
18 ## 02110-1301, USA. |
|
6239
|
19 |
|
|
20 ## -*- texinfo -*- |
|
|
21 ## @deftypefn {Function File} {} tand (@var{x}) |
|
|
22 ## Compute the tangent of an angle in degrees. Returns zero for elements |
|
|
23 ## of for which @code{@var{x}/180} is an integer and @code{Inf} for elements |
|
6252
|
24 ## where @code{(@var{x}-90)/180} is an integer. |
|
6239
|
25 ## @seealso{tan, cosd, sind, acosd, asind, atand} |
|
|
26 ## @end deftypefn |
|
|
27 |
|
|
28 function y = tand (x) |
|
|
29 if (nargin != 1) |
|
|
30 print_usage (); |
|
|
31 endif |
|
|
32 I0 = x / 180; |
|
|
33 I90 = (x-90) / 180; |
|
|
34 y = tan (I0 .* pi); |
|
|
35 y(I0 == round (I0) & finite (I0)) = 0; |
|
|
36 y(I90 == round (I90) & finite (I90)) = Inf; |
|
|
37 endfunction; |
|
|
38 |
|
|
39 %!error(tand()) |
|
|
40 %!error(tand(1,2)) |
|
|
41 %!assert(tand(10:10:80),tan(pi*[10:10:80]/180),-10*eps) |
|
|
42 %!assert(tand([0,180,360]) == 0) |
|
|
43 %!assert(tand([90,270]) == Inf) |
