FittedBondDiscountCurve Class Reference

Discount curve fitted to a set of fixed-coupon bonds. More...

#include <ql/termstructures/yield/fittedbonddiscountcurve.hpp>

Inheritance diagram for FittedBondDiscountCurve:

Classes
class	FittingMethod
	Base fitting method used to construct a fitted bond discount curve. More...

Public Member Functions
Constructors
	FittedBondDiscountCurve (Natural settlementDays, const Calendar &calendar, const std::vector< boost::shared_ptr< BondHelper > > &bonds, const DayCounter &dayCounter, const FittingMethod &fittingMethod, Real accuracy=1.0e-10, Size maxEvaluations=10000, const Array &guess=Array(), Real simplexLambda=1.0)
	reference date based on current evaluation date
	FittedBondDiscountCurve (const Date &referenceDate, const std::vector< boost::shared_ptr< BondHelper > > &bonds, const DayCounter &dayCounter, const FittingMethod &fittingMethod, Real accuracy=1.0e-10, Size maxEvaluations=10000, const Array &guess=Array(), Real simplexLambda=1.0)
	curve reference date fixed for life of curve
	FittedBondDiscountCurve (Natural settlementDays, const Calendar &calendar, const std::vector< boost::shared_ptr< FixedRateBondHelper > > &bonds, const DayCounter &dayCounter, const FittingMethod &fittingMethod, Real accuracy=1.0e-10, Size maxEvaluations=10000, const Array &guess=Array(), Real simplexLambda=1.0)
	reference date based on current evaluation date
	FittedBondDiscountCurve (const Date &referenceDate, const std::vector< boost::shared_ptr< FixedRateBondHelper > > &bonds, const DayCounter &dayCounter, const FittingMethod &fittingMethod, Real accuracy=1.0e-10, Size maxEvaluations=10000, const Array &guess=Array(), Real simplexLambda=1.0)
	curve reference date fixed for life of curve
Inspectors
Size	numberOfBonds () const
	total number of bonds used to fit the yield curve
Date	maxDate () const
	the latest date for which the curve can return values
const FittingMethod &	fitResults () const
	class holding the results of the fit
Observer interface
void	update ()
Public Member Functions inherited from YieldTermStructure
	YieldTermStructure (const DayCounter &dc=DayCounter(), const std::vector< Handle< Quote > > &jumps=std::vector< Handle< Quote > >(), const std::vector< Date > &jumpDates=std::vector< Date >())
	YieldTermStructure (const Date &referenceDate, const Calendar &cal=Calendar(), const DayCounter &dc=DayCounter(), const std::vector< Handle< Quote > > &jumps=std::vector< Handle< Quote > >(), const std::vector< Date > &jumpDates=std::vector< Date >())
	YieldTermStructure (Natural settlementDays, const Calendar &cal, const DayCounter &dc=DayCounter(), const std::vector< Handle< Quote > > &jumps=std::vector< Handle< Quote > >(), const std::vector< Date > &jumpDates=std::vector< Date >())
DiscountFactor	discount (const Date &d, bool extrapolate=false) const
DiscountFactor	discount (Time t, bool extrapolate=false) const
InterestRate	zeroRate (const Date &d, const DayCounter &resultDayCounter, Compounding comp, Frequency freq=Annual, bool extrapolate=false) const
InterestRate	zeroRate (Time t, Compounding comp, Frequency freq=Annual, bool extrapolate=false) const
InterestRate	forwardRate (const Date &d1, const Date &d2, const DayCounter &resultDayCounter, Compounding comp, Frequency freq=Annual, bool extrapolate=false) const
InterestRate	forwardRate (const Date &d, const Period &p, const DayCounter &resultDayCounter, Compounding comp, Frequency freq=Annual, bool extrapolate=false) const
InterestRate	forwardRate (Time t1, Time t2, Compounding comp, Frequency freq=Annual, bool extrapolate=false) const
const std::vector< Date > &	jumpDates () const
const std::vector< Time > &	jumpTimes () const
void	update ()
Public Member Functions inherited from TermStructure
	TermStructure (const DayCounter &dc=DayCounter())
	default constructor More...
	TermStructure (const Date &referenceDate, const Calendar &calendar=Calendar(), const DayCounter &dc=DayCounter())
	initialize with a fixed reference date
	TermStructure (Natural settlementDays, const Calendar &, const DayCounter &dc=DayCounter())
	calculate the reference date based on the global evaluation date
virtual DayCounter	dayCounter () const
	the day counter used for date/time conversion
Time	timeFromReference (const Date &date) const
	date/time conversion
virtual Time	maxTime () const
	the latest time for which the curve can return values
virtual const Date &	referenceDate () const
	the date at which discount = 1.0 and/or variance = 0.0
virtual Calendar	calendar () const
	the calendar used for reference and/or option date calculation
virtual Natural	settlementDays () const
	the settlementDays used for reference date calculation
Public Member Functions inherited from Observer
	Observer (const Observer &)
Observer &	operator= (const Observer &)
std::pair< std::set < boost::shared_ptr < Observable > >::iterator, bool >	registerWith (const boost::shared_ptr< Observable > &)
Size	unregisterWith (const boost::shared_ptr< Observable > &)
void	unregisterWithAll ()
Public Member Functions inherited from Observable
	Observable (const Observable &)
Observable &	operator= (const Observable &)
void	notifyObservers ()
Public Member Functions inherited from Extrapolator
void	enableExtrapolation (bool b=true)
	enable extrapolation in subsequent calls
void	disableExtrapolation (bool b=true)
	disable extrapolation in subsequent calls
bool	allowsExtrapolation () const
	tells whether extrapolation is enabled
Public Member Functions inherited from LazyObject
void	recalculate ()
void	freeze ()
void	unfreeze ()

Friends
class	FittingMethod

Additional Inherited Members
Calculations
This method must be implemented in derived classes to perform the actual calculations. When it is called, range check has already been performed; therefore, it must assume that extrapolation is required.
Protected Member Functions inherited from TermStructure
void	checkRange (const Date &d, bool extrapolate) const
	date-range check
void	checkRange (Time t, bool extrapolate) const
	time-range check
Protected Member Functions inherited from LazyObject
virtual void	calculate () const
Protected Attributes inherited from TermStructure
bool	moving_
bool	updated_
Calendar	calendar_
Protected Attributes inherited from LazyObject
bool	calculated_
bool	frozen_

Detailed Description

Discount curve fitted to a set of fixed-coupon bonds.

This class fits a discount function over a set of bonds, using a user defined fitting method. The discount function is fit in such a way so that all cashflows of all input bonds, when discounted using , will reproduce the set of input bond prices in an optimized sense. Minimized price errors are weighted by the inverse of their respective bond duration.

The FittedBondDiscountCurve class acts as a generic wrapper, while its inner class FittingMethod provides the implementation details. Developers thus need only derive new fitting methods from the latter.

Example: compares various bond discount curve fitting methodologies

Warning:

The method can be slow if there are many bonds to fit. Speed also depends on the particular choice of fitting method chosen and its convergence properties under optimization. See also todo list for BondDiscountCurveFittingMethod.

Possible enhancements:

refactor the bond helper class so that it is pure virtual and returns a generic bond or its cash flows. Derived classes would include helpers for fixed-rate and zero-coupon bonds. In this way, both bonds and bills can be used to fit a discount curve using the exact same machinery. At present, only fixed-coupon bonds are supported. An even better way to move forward might be to get rate helpers to return cashflows, in which case this class could be used to fit any set of cash flows, not just bonds.

Possible enhancements:

add more fitting diagnostics: smoothness, standard deviation, student-t test, etc. Generic smoothness method may be useful for smoothing splines fitting. See Fisher, M., D. Nychka and D. Zervos: "Fitting the term structure of interest rates with smoothing splines." Board of Governors of the Federal Reserve System, Federal Resere Board Working Paper, 95-1.

Possible enhancements:

add extrapolation routines

Examples:

FittedBondCurve.cpp.