QuantLib: a free/open-source library for quantitative finance
fully annotated source code - version 1.34
Loading...
Searching...
No Matches
bisection.hpp
Go to the documentation of this file.
1/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2
3/*
4 Copyright (C) 2000, 2001, 2002, 2003 RiskMap srl
5
6 This file is part of QuantLib, a free-software/open-source library
7 for financial quantitative analysts and developers - http://quantlib.org/
8
9 QuantLib is free software: you can redistribute it and/or modify it
10 under the terms of the QuantLib license. You should have received a
11 copy of the license along with this program; if not, please email
12 <quantlib-dev@lists.sf.net>. The license is also available online at
13 <http://quantlib.org/license.shtml>.
14
15 This program is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 FOR A PARTICULAR PURPOSE. See the license for more details.
18*/
19
20/*! \file bisection.hpp
21 \brief bisection 1-D solver
22*/
23
24#ifndef quantlib_solver1d_bisection_h
25#define quantlib_solver1d_bisection_h
26
27#include <ql/math/solver1d.hpp>
28
29namespace QuantLib {
30
31 //! %Bisection 1-D solver
32 /*! \test the correctness of the returned values is tested by
33 checking them against known good results.
34
35 \ingroup solvers
36 */
37 class Bisection : public Solver1D<Bisection> {
38 public:
39 template <class F>
40 Real solveImpl(const F& f,
41 Real xAccuracy) const {
42
43 /* The implementation of the algorithm was inspired by
44 Press, Teukolsky, Vetterling, and Flannery,
45 "Numerical Recipes in C", 2nd edition, Cambridge
46 University Press
47 */
48
49 Real dx, xMid, fMid;
50
51 // Orient the search so that f>0 lies at root_+dx
52 if (fxMin_ < 0.0) {
53 dx = xMax_-xMin_;
54 root_ = xMin_;
55 } else {
56 dx = xMin_-xMax_;
57 root_ = xMax_;
58 }
59
61 dx /= 2.0;
62 xMid = root_+dx;
63 fMid = f(xMid);
65 if (fMid <= 0.0)
66 root_ = xMid;
67 if (std::fabs(dx) < xAccuracy || (close(fMid, 0.0))) {
68 f(root_);
70 return root_;
71 }
72 }
73 QL_FAIL("maximum number of function evaluations ("
74 << maxEvaluations_ << ") exceeded");
75 }
76 };
77
78}
79
80#endif
Bisection 1-D solver
Definition: bisection.hpp:37
Real solveImpl(const F &f, Real xAccuracy) const
Definition: bisection.hpp:40
Base class for 1-D solvers.
Definition: solver1d.hpp:67
#define QL_FAIL(message)
throw an error (possibly with file and line information)
Definition: errors.hpp:92
QL_REAL Real
real number
Definition: types.hpp:50
Definition: any.hpp:35
bool close(const Quantity &m1, const Quantity &m2, Size n)
Definition: quantity.cpp:163
Real F
Definition: sabr.cpp:200
Abstract 1-D solver class.