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comparison scripts/elfun/tand.m @ 6239:82185e38eea8

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[project @ 2007-01-10 22:53:58 by jwe]
author jwe
date Wed, 10 Jan 2007 22:53:59 +0000
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children 738c97e101eb
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6238:3ecd8d2c5654 6239:82185e38eea8
1 ## Copyright (C) 2006 David Bateman <dbateman@free.fr>
2 ##
3 ## This program is free software; you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation; either version 2 of the License, or
6 ## (at your option) any later version.
7 ##
8 ## This program is distributed in the hope that it will be useful,
9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 ## GNU General Public License for more details.
12 ##
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program; if not, write to the Free Software
15 ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16
17 ## -*- texinfo -*-
18 ## @deftypefn {Function File} {} tand (@var{x})
19 ## Compute the tangent of an angle in degrees. Returns zero for elements
20 ## of for which @code{@var{x}/180} is an integer and @code{Inf} for elements
21 ## where @code{(@var{x}-90}/180} is an integer.
22 ## @seealso{tan, cosd, sind, acosd, asind, atand}
23 ## @end deftypefn
24
25 function y = tand (x)
26 if (nargin != 1)
27 print_usage ();
28 endif
29 I0 = x / 180;
30 I90 = (x-90) / 180;
31 y = tan (I0 .* pi);
32 y(I0 == round (I0) & finite (I0)) = 0;
33 y(I90 == round (I90) & finite (I90)) = Inf;
34 endfunction;
35
36 %!error(tand())
37 %!error(tand(1,2))
38 %!assert(tand(10:10:80),tan(pi*[10:10:80]/180),-10*eps)
39 %!assert(tand([0,180,360]) == 0)
40 %!assert(tand([90,270]) == Inf)