Mercurial > octave-dspies
view libinterp/corefcn/givens.cc @ 19010:3fb030666878 draft default tip dspies
Added special-case logical-indexing function
* logical-index.h (New file) : Logical-indexing function. May be called on
octave_value types via call_bool_index
* nz-iterators.h : Add base-class nz_iterator for iterator types. Array has
template bool for whether to internally store row-col or compute on the fly
Add skip_ahead method which skips forward to the next nonzero after its
argument
Add flat_index for computing octave_idx_type index of current position (with
assertion failure in the case of overflow)
Move is_zero to separate file
* ov-base-diag.cc, ov-base-mat.cc, ov-base-sparse.cc, ov-perm.cc
(do_index_op): Add call to call_bool_index in logical-index.h
* Array.h : Move forward-declaration for array_iterator to separate header file
* dim-vector.cc (dim_max): Refers to idx-bounds.h (max_idx)
* array-iter-decl.h (New file): Header file for forward declaration of
array-iterator
* direction.h : Add constants fdirc and bdirc to avoid having to reconstruct
them
* dv-utils.h, dv-utils.cc (New files) :
Utility functions for querying and constructing dim-vectors
* idx-bounds.h (New file) :
Utility constants and functions for determining whether things will overflow
the maximum allowed bounds
* interp-idx.h (New function : to_flat_idx) : Converts row-col pair to linear
index of octave_idx_type
* is-zero.h (New file) : Function for determining whether an element is zero
* logical-index.tst : Add tests for correct return-value dimensions and large
sparse matrix behavior
author | David Spies <dnspies@gmail.com> |
---|---|
date | Fri, 25 Jul 2014 13:39:31 -0600 |
parents | 175b392e91fe |
children |
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/* Copyright (C) 1996-2013 John W. Eaton This file is part of Octave. Octave is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. Octave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Octave; see the file COPYING. If not, see <http://www.gnu.org/licenses/>. */ // Originally written by A. S. Hodel <scotte@eng.auburn.edu> #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "defun.h" #include "error.h" #include "oct-obj.h" DEFUN (givens, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {@var{g} =} givens (@var{x}, @var{y})\n\ @deftypefnx {Built-in Function} {[@var{c}, @var{s}] =} givens (@var{x}, @var{y})\n\ @tex\n\ Return a $2\\times 2$ orthogonal matrix\n\ $$\n\ G = \\left[\\matrix{c & s\\cr -s'& c\\cr}\\right]\n\ $$\n\ such that\n\ $$\n\ G \\left[\\matrix{x\\cr y}\\right] = \\left[\\matrix{\\ast\\cr 0}\\right]\n\ $$\n\ with $x$ and $y$ scalars.\n\ @end tex\n\ @ifnottex\n\ Return a 2 by 2 orthogonal matrix\n\ @code{@var{g} = [@var{c} @var{s}; -@var{s}' @var{c}]} such that\n\ @code{@var{g} [@var{x}; @var{y}] = [*; 0]} with @var{x} and @var{y} scalars.\n\ @end ifnottex\n\ \n\ For example:\n\ \n\ @example\n\ @group\n\ givens (1, 1)\n\ @result{} 0.70711 0.70711\n\ -0.70711 0.70711\n\ @end group\n\ @end example\n\ @end deftypefn") { octave_value_list retval; int nargin = args.length (); if (nargin != 2 || nargout > 2) { print_usage (); return retval; } else { if (args(0).is_single_type () || args(1).is_single_type ()) { if (args(0).is_complex_type () || args(1).is_complex_type ()) { FloatComplex cx = args(0).float_complex_value (); FloatComplex cy = args(1).float_complex_value (); if (! error_state) { FloatComplexMatrix result = Givens (cx, cy); if (! error_state) { switch (nargout) { case 0: case 1: retval(0) = result; break; case 2: retval(1) = result (0, 1); retval(0) = result (0, 0); break; default: error ("givens: invalid number of output arguments"); break; } } } } else { float x = args(0).float_value (); float y = args(1).float_value (); if (! error_state) { FloatMatrix result = Givens (x, y); if (! error_state) { switch (nargout) { case 0: case 1: retval(0) = result; break; case 2: retval(1) = result (0, 1); retval(0) = result (0, 0); break; default: error ("givens: invalid number of output arguments"); break; } } } } } else { if (args(0).is_complex_type () || args(1).is_complex_type ()) { Complex cx = args(0).complex_value (); Complex cy = args(1).complex_value (); if (! error_state) { ComplexMatrix result = Givens (cx, cy); if (! error_state) { switch (nargout) { case 0: case 1: retval(0) = result; break; case 2: retval(1) = result (0, 1); retval(0) = result (0, 0); break; default: error ("givens: invalid number of output arguments"); break; } } } } else { double x = args(0).double_value (); double y = args(1).double_value (); if (! error_state) { Matrix result = Givens (x, y); if (! error_state) { switch (nargout) { case 0: case 1: retval(0) = result; break; case 2: retval(1) = result (0, 1); retval(0) = result (0, 0); break; default: error ("givens: invalid number of output arguments"); break; } } } } } } return retval; } /* %!assert (givens (1,1), [1, 1; -1, 1] / sqrt (2), 2*eps) %!assert (givens (1,0), eye (2)) %!assert (givens (0,1), [0, 1; -1 0]) %!error givens () %!error givens (1) */