Mercurial > octave-dspies
view libinterp/corefcn/rcond.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) 2008-2013 David Bateman 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/>. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "defun.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" #include "utils.h" DEFUN (rcond, args, , "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {@var{c} =} rcond (@var{A})\n\ Compute the 1-norm estimate of the reciprocal condition number as returned\n\ by @sc{lapack}. If the matrix is well-conditioned then @var{c} will be near\n\ 1 and if the matrix is poorly conditioned it will be close to zero.\n\ \n\ The matrix @var{A} must not be sparse. If the matrix is sparse then\n\ @code{condest (@var{A})} or @code{rcond (full (@var{A}))} should be used\n\ instead.\n\ @seealso{cond, condest}\n\ @end deftypefn") { octave_value retval; int nargin = args.length (); if (nargin != 1) print_usage (); else if (args(0).is_sparse_type ()) error ("rcond: for sparse matrices use 'rcond (full (a))' or 'condest (a)' instead"); else if (args(0).is_single_type ()) { if (args(0).is_complex_type ()) { FloatComplexMatrix m = args(0).float_complex_matrix_value (); MatrixType mattyp; retval = m.rcond (mattyp); args(0).matrix_type (mattyp); } else { FloatMatrix m = args(0).float_matrix_value (); MatrixType mattyp; retval = m.rcond (mattyp); args(0).matrix_type (mattyp); } } else if (args(0).is_complex_type ()) { ComplexMatrix m = args(0).complex_matrix_value (); MatrixType mattyp; retval = m.rcond (mattyp); args(0).matrix_type (mattyp); } else { Matrix m = args(0).matrix_value (); MatrixType mattyp; retval = m.rcond (mattyp); args(0).matrix_type (mattyp); } return retval; } /* %!assert (rcond (eye (2)), 1) %!assert (rcond (ones (2)), 0) %!assert (rcond ([1 1; 2 1]), 1/9) %!assert (rcond (magic (4)), 0, eps) %!shared x, sx %! x = [-5.25, -2.25; -2.25, 1] * eps () + ones (2) / 2; %! sx = [-5.25, -2.25; -2.25, 1] * eps ("single") + ones (2) / 2; %!assert (rcond (x) < eps ()); %!assert (rcond (sx) < eps ('single')); %!assert (rcond (x*i) < eps ()); %!assert (rcond (sx*i) < eps ('single')); */