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comparison src/DLD-FUNCTIONS/givens.cc @ 3372:f16c2ce14886

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[project @ 1999-11-23 19:07:09 by jwe]
author jwe
date Tue, 23 Nov 1999 19:07:18 +0000
parents 38de16594cb4
children 3e3e14ad5149
comparison
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3371:86873384cd10 3372:f16c2ce14886
29 #include "defun-dld.h" 29 #include "defun-dld.h"
30 #include "error.h" 30 #include "error.h"
31 #include "oct-obj.h" 31 #include "oct-obj.h"
32 32
33 DEFUN_DLD (givens, args, nargout, 33 DEFUN_DLD (givens, args, nargout,
34 "G = givens (X, Y)\n\ 34 "-*- texinfo -*-
35 @deftypefn {Loadable Function} {@var{G} =} givens (@var{x}, @var{y})\n\
36 @deftypefnx {Loadable Function} {[@var{c}, @var{s}] =} givens (@var{x}, @var{y})\n\
37 @iftex\n\
38 @tex\n\
39 Return a $2\\times 2$ orthogonal matrix\n\
40 $$\n\
41 G = \\left[\\matrix{c & s\\cr -s'& c\\cr}\\right]\n\
42 $$\n\
43 such that\n\
44 $$\n\
45 G \\left[\\matrix{x\\cr y}\\right] = \\left[\\matrix{\\ast\\cr 0}\\right]\n\
46 $$\n\
47 with $x$ and $y$ scalars.\n\
48 @end tex\n\
49 @end iftex\n\
50 @ifinfo\n\
51 Return a 2 by 2 orthogonal matrix\n\
52 @code{@var{G} = [@var{c} @var{s}; -@var{s}' @var{c}]} such that\n\
53 @code{@var{G} [@var{x}; @var{y}] = [*; 0]} with @var{x} and @var{y} scalars.\n\
54 @end ifinfo\n\
35 \n\ 55 \n\
36 compute orthogonal matrix G = [c s; -conj (s) c]\n\ 56 For example,\n\
37 such that G [x; y] = [*; 0] (x, y scalars)\n\
38 \n\ 57 \n\
39 [c, s] = givens (x, y) returns the (c, s) values themselves.") 58 @example\n\
59 @group\n\
60 givens (1, 1)\n\
61 @result{} 0.70711 0.70711\n\
62 -0.70711 0.70711\n\
63 @end group\n\
64 @end example\n\
65 @end deftypefn")
40 { 66 {
41 octave_value_list retval; 67 octave_value_list retval;
42 68
43 int nargin = args.length (); 69 int nargin = args.length ();
44 70