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comparison scripts/linear-algebra/planerot.m @ 19361:1faae07afbd8

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Overhaul givens and planerot functions. * givens.cc (Fgivens): Redo docstring. Remove useless default to detect nargout > 2 in switch statements. * planerot.m: Redo docstring. Add input validation. Add BIST tests for input validation.
author Rik <rik@octave.org>
date Sat, 27 Sep 2014 13:41:57 -0700
parents d63878346099
children 4197fc428c7d
comparison
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19360:9163a6e9b096 19361:1faae07afbd8
15 ## You should have received a copy of the GNU General Public License 15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, see 16 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>. 17 ## <http://www.gnu.org/licenses/>.
18 18
19 ## -*- texinfo -*- 19 ## -*- texinfo -*-
20 ## @deftypefn {Function File} {[@var{g}, @var{y}] =} planerot (@var{x}) 20 ## @deftypefn {Function File} {[@var{G}, @var{y}] =} planerot (@var{x})
21 ## Given a two-element column vector, returns the 21 ## Given a two-element column vector, return the
22 ## @tex 22 ## @tex
23 ## $2 \times 2$ orthogonal matrix 23 ## $2 \times 2$ orthogonal matrix
24 ## @end tex 24 ## @end tex
25 ## @ifnottex 25 ## @ifnottex
26 ## 2 by 2 orthogonal matrix 26 ## 2 by 2 orthogonal matrix
29 ## @code{@var{y} = @var{g} * @var{x}} and @code{@var{y}(2) = 0}. 29 ## @code{@var{y} = @var{g} * @var{x}} and @code{@var{y}(2) = 0}.
30 ## @seealso{givens} 30 ## @seealso{givens}
31 ## @end deftypefn 31 ## @end deftypefn
32 32
33 function [G, y] = planerot (x) 33 function [G, y] = planerot (x)
34
35 if (nargin != 1)
36 print_usage ();
37 elseif (! (isvector (x) && numel (x) == 2))
38 error ("planerot: X must be a 2-element vector");
39 endif
40
34 G = givens (x(1), x(2)); 41 G = givens (x(1), x(2));
35 y = G * x(:); 42 y = G * x(:);
43
36 endfunction 44 endfunction
37 45
38 46
39 %!test 47 %!test
40 %! x = [3 4]; 48 %! x = [3 4];
41 %! [g y] = planerot (x); 49 %! [g y] = planerot (x);
42 %! assert (g, [x(1) x(2); -x(2) x(1)] / sqrt (x(1)^2 + x(2)^2), 2e-8); 50 %! assert (g, [x(1) x(2); -x(2) x(1)] / sqrt (x(1)^2 + x(2)^2), 2e-8);
43 %! assert (y(2), 0, 2e-8); 51 %! assert (y(2), 0, 2e-8);
44 52
45 %!error planerot ([0])
46 %!error planerot ([0 0 0])
47 %!error planerot () 53 %!error planerot ()
54 %!error planerot (1,2)
55 %!error <X must be a 2-element vector> planerot (ones (2,2))
56 %!error <X must be a 2-element vector> planerot ([0 0 0])
48 57